# Kuuma VF 100 not heating my house! Help!



## bropp (Jan 18, 2020)

For the last five years I've been reading great things about the vf100 and have been wanting one. I finally purchased one and am very disappointed- I can't get it to heat my house!  The firebox is a blast furnace but the plenum feels cool. I don't know why the heat won't leave the firebox. I  can't get my house above 60 and its in the upper 50s in the morning and it's been super warm outside- lows 20 above and highs close to thirty! I  have a thermometer on the registers and usually reads 72. I don't know how to get more heat from it. I insulated the plenum and put a probe in one foot above the plenum- when the furnace is roaring on the highest setting it reads 90 degrees.

I live in a 3000 sq ft house with two garage doors in the lower level. It is essentially a 1500 sq ft ranch with a Wood walled 2x6 walkout basement. The entire thing has r19 walls. The garage doors are insulated and plugged around the edges, I don't use them.  House was built in 94 and has good insulation .
I've been burning wood my entire life. I am burning dry Ash and maple between 15-20 percent on the moisture meter.
6 inch class a chimney with barometric damper. I've tried every setting on the damper and just got a Dwyer mkii to check, but think its okay as i have flue temps between 200-250. Chimney goes through a thimble and is about 25 feet tall.
I made a duct system for it- not ideal but am moving it next year.  Has 10x20 trunk with 4 8 in takeoffs. I've played all around with changing the static duct pressure to increase air temp. Cold air return comes from up stairs.

The air coming out just feels cold. I've talked with Dale about a dozen times and he's been very nice, but it hasn't gotten any warmer.
My wire is furious about this whole problem and wants it returned immediately. She grew up in an uninsulated farmhouse with a hot blast that was always 80 inside  even when  it's -35 outside. When I go there the plenum is always HOT when it calls for heat. Mine is cold.
Help! Is the Kumma actually as good as everyone says? I really regret buying it!
This has been going on for over two months
 I've tried everything


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## Gbawol42 (Jan 18, 2020)

I am sure @brenndatomu and @JRHAWK9 will help you out when they see this post. 

Something definitely sounds fishy, if it's in the 30's  outside you should be cooking yourself out of the home, especially with the proper seasoned wood (which is usually the culprit 95% of the time)

I tagged two guys that are helpful for the vf100, I myself have a drolet heatmax, so little different setup.  I won't be much help to ya.


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## bropp (Jan 18, 2020)

Gbawol42 said:


> I am sure @brenndatomu and @JRHAWK9 will help you out when they see this post.
> 
> Something definitely sounds fishy, if it's in the 30's  outside you should be cooking yourself out of the home, especially with the proper seasoned wood (which is usually the culprit 95% of the time)
> 
> I tagged two guys that are helpful for the vf100, I myself have a drolet heatmax, so little different setup.  I won't be much help to ya.


Thanks!


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## brenndatomu (Jan 18, 2020)

bropp said:


> For the last five years I've been reading great things about the vf100 and have been wanting one. I finally purchased one and am very disappointed- I can't get it to heat my house!  The firebox is a blast furnace but the plenum feels cool. I don't know why the heat won't leave the firebox. I  can't get my house above 60 and its in the upper 50s in the morning and it's been super warm outside- lows 20 above and highs close to thirty! I  have a thermometer on the registers and usually reads 72. I don't know how to get more heat from it. I insulated the plenum and put a probe in one foot above the plenum- when the furnace is roaring on the highest setting it reads 90 degrees.
> 
> I live in a 3000 sq ft house with two garage doors in the lower level. It is essentially a 1500 sq ft ranch with a Wood walled 2x6 walkout basement. The entire thing has r19 walls. The garage doors are insulated and plugged around the edges, I don't use them.  House was built in 94 and has good insulation .
> I've been burning wood my entire life. I am burning dry Ash and maple between 15-20 percent on the moisture meter.
> ...


There has got to be something really wrong here...the smaller VF200 should be able run you clean out of the house with only 1500 sq ft! A VF100 should be total overkill honestly.
What is your draft set at? That 200-250 pipe temp you mentioned...is that internal or external? If that's internal, that's way too low...assuming you are measuring it before the barometric damper (baro)
You said cold air return comes from upstairs...is that ducted directly to the Kuuma blower box, or does it just flow down the stairs? What is the basement floor temp vs the ceiling? 
Has Dale had you check to make sure the baffles are properly in place?
How long have you been using it?
Is the blower on high, or low? Try it the other way much?
90* in your plenum is very low...I get in the upper 90s before the fire is even properly established...110* after things have settled in...115* at the peak for a small wood load, and in the 120s at peak with a large wood load.
Something is most certainly very wrong here...


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## bropp (Jan 18, 2020)

brenndatomu said:


> There has got to be something really wrong here...the smaller VF200 should be able run you clean out of the house with only 1500 sq ft! A VF100 should be total overkill honestly.
> What is your draft set at? That 200-250 pipe temp you mentioned...is that internal or external? If that's internal, that's way too low...assuming you are measuring it before the barometric damper (baro)
> You said cold air return comes from upstairs...is that ducted directly to the Kuuma blower box, or does it just flow down the stairs? What is the basement floor temp vs the ceiling?
> Has Dale had you check to make sure the baffles are properly in place?
> ...


Dale said the inside flue temp should be around 225-275 and no more. I've had the barometric set every which way with nothing but cresote one way and a shorter burn the other. The cold air return is ducted right into the box. It doesn't take in hardly any basement air, I even taped it tight. I've talked to Dale and tried the baffles every which way and run the want every which way too.


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## brenndatomu (Jan 18, 2020)

225-275 is too low unless that is the external pipe temp...internally mine runs in the 300s...or high 200s if it's been on pilot a long time...it will go close to, or a little over 400 if the damper is on 3 for long.
So 300 to 350 is it's normal range when it's doing it's c-1-c-1 thing during the early hours of the burn. Other owners get about the same temps...


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## brenndatomu (Jan 18, 2020)

Your draft should be -0.04" to -0.06"...I usually run around -0.045"...


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## bropp (Jan 18, 2020)

brenndatomu said:


> 225-275 is too low unless that is the external pipe temp...internally mine runs in the 300s...or high 200s if it's been on pilot a long time...it will go close to, or a little over 400 if the damper is on 3 for long.
> So 300 to 350 is it's normal range when it's doing it's c-1-c-1 thing during the early hours of the burn. Other owners get about the same temps...


Thanks!  Just got the mark II and will check the WC today


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## brenndatomu (Jan 18, 2020)

What was your main heat source before?
How much fuel did you use in a year?


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## maple1 (Jan 18, 2020)

Why not post the pic here that you posted on that other forum? From that one, your baro damper is installed incorrectly. 

Post that pic for starters. And maybe more. You will get more overall Kuuma specific feedback here - I think.


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## brenndatomu (Jan 18, 2020)

maple1 said:


> Why not post the pic here that you posted on that other forum? From that one, your baro damper is installed incorrectly.
> 
> Post that pic for starters. And maybe more. You will get more overall Kuuma specific feedback here - I think.


I agree...we need pics...from the pic you put up on AS, your return air is too small...IIRC, you need 180 sq in. on the supply plenum/ducts...and around 200 sq in for the return ducts...about 10% more than the supply.
You look to have a 12-14" flex duct there...so assuming its 14", that's only 154" sq in...and flex duct actually "flows smaller" than its nominal size.


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## JRHAWK9 (Jan 18, 2020)

Is it installed in your garage?  Is it installed in the same heating envelope of what you are trying to heat?

What are your return temps.....the temp inside the blower box?

Back with my stock blower setup, I was sucking in 65° air and my plenum temps were 100-105° with the Kuuma on low and the blower on low.  Kuuma on high and blower on high I would see 105°+° plenum temps, IIRC.  I never had real high plenum temps with the stock blower setup and pulling my air off the basement floor.  The one time I remember measuring my vent temp upstairs it was 90° back then.

The stock setup heated our house just fine in temps above 10°.  Before heating with wood, we used to average about 1,200 - 1,300 gallons of LP a year keeping the house at 68°.

We are going to need way more temp samples and photos in order to help.


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## bropp (Jan 18, 2020)

maple1 said:


> Why not post the pic here that you posted on that other forum? From that one, your baro damper is installed incorrectly.
> 
> Post that pic for starters. And maybe more. You will get more overall Kuuma specific feedback here - I think.


I am thinking that it is not drawing enough. I leveled the damper both ways to see what happens.


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## brenndatomu (Jan 18, 2020)

I would straighten that stove pipe out...just use 90s so that the pipe is vertical and the baro can be installed properly...with 25' of class A chimney you will not have draft issues doing this (assuming that's why you angled it)
With the baro just taped on if you ever have a backpuff (unlikely with a Kuuma) that baro will become a projectile.


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## bropp (Jan 18, 2020)

brenndatomu said:


> I would straighten that stove pipe out...just use 90s so that the pipe is vertical and the baro can be installed properly...with 25' of class A chimney you will not have draft issues doing this (assuming that's why you angled it)
> With the baro just taped on if you ever have a backpuff (unlikely with a Kuuma) that baro will become a projectile.


Thanks!


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## JRHAWK9 (Jan 18, 2020)

bropp said:


> I am thinking that it is not drawing enough.



May be part of the issue but not the smoking gun.  If that was the only issue, a high return SP....meaning starving it for return air, would result in higher plenum temps due do the lack of volume of air passing through the air jacket.  

All of us are just guessing at this point as we have very few data points to go off of.  We need to know your return air temp and your plenum temp....so we can see what your dT is.  Register temps taken at the same time of the other two.  Garage temp (looks to be the garage anyway), where the furnace is located.  Assuming the space you are heating is ABOVE the furnace....seeing you stated the garage is the lower level.        

For some of us, wood furnaces are not just a plug and play appliance.  Some setups/houses need some tweaking done to the return/supply air to get them to perform at max performance and some don't.  I was one of them who did.


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## JRHAWK9 (Jan 19, 2020)

I would also like to know if the furnace is going to pilot ('c') at whatever burn set point (low to high) you have the computer set at? If the computer is going to pilot, it's meeting internal firebox temps for the level of burn the computer is set for and burning the wood as designed.


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## bropp (Jan 19, 2020)

JRHAWK9 said:


> May be part of the issue but not the smoking gun.  If that was the only issue, a high return SP....meaning starving it for return air, would result in higher plenum temps due do the lack of volume of air passing through the air jacket.
> 
> All of us are just guessing at this point as we have very few data points to go off of.  We need to know your return air temp and your plenum temp....so we can see what your dT is.  Register temps taken at the same time of the other two.  Garage temp (looks to be the garage anyway), where the furnace is located.  Assuming the space you are heating is ABOVE the furnace....seeing you stated the garage is the lower level.
> 
> For some of us, wood furnaces are not just a plug and play appliance.  Some setups/houses need some tweaking done to the return/supply air to get them to perform at max performance and some don't.  I was one of them who did.


I have been observing temps evey day for the last two months. They are almost always the same: living room temp 62 bedroom 64 basement 64 garage 60.
Return air temp 60-64. Plenum temp one foot above furnace 90-95. Yesterday with the barometric damper at 8 it hit 102, the highest ever. WC was .12 last night with barometric damper closed, but normally.06.  normal register temp in bedroom is 72-75.
Last night the bedroom register temp was over 80 at peak burn, highest ever. 
The house was 58 when I woke up, and I put my best maple pieces in last night.
Computer setting is always on the highest setting unless I'm gone more than 10 hours. It doesn't seem to produce more heat on highest setting or medium for some reason.

I was really hopeful I wasn't getting a high enough flue temp after yesterday's comments, and it did make the register temp go up by several degrees when the flue temp was 350-400 when the display read "c"
Thanks guys!


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## bropp (Jan 19, 2020)

JRHAWK9 said:


> I would also like to know if the furnace is going to pilot ('c') at whatever burn set point (low to high) you have the computer set at? If the computer is going to pilot, it's meeting internal firebox temps for the level of burn the computer is set for and burning the wood as designed.


The computer goes to pilot to 1 all the time. It is set at the highest setting.


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## woodey (Jan 19, 2020)

What temp do you have your lower limit switch set at and any thoughts from Brenn and JR about the placement of the switch?


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## brenndatomu (Jan 19, 2020)

bropp said:


> I have been observing temps evey day for the last two months.


OK, that answers one of my original questions...how long have you been using it?
Have you cleaned your heat exchanger area yet? If you had any crappy wood in that time (especially early on) it could have put a coat of crude on everything and it doesn't take much to start losing heat exchange efficiency...even with burning perfectly normally and just a light coat of fly ash on everything, I (and others) notice a difference in plenum temps vs exhaust temps right after cleaning...I try to clean 2-3 times per heating season. (you will notice exhaust temps drop, and plenum temps go up)


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## brenndatomu (Jan 19, 2020)

woodey said:


> thoughts from Brenn and JR about the placement of the switch?


High in the plenum...


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## bropp (Jan 19, 2020)

brenndatomu said:


> OK, that answers one of my original questions...how long have you been using it?
> Have you cleaned your heat exchanger area yet? If you had any crappy wood in that time (especially early on) it could have put a coat of crude on everything and it doesn't take much to start losing heat exchange efficiency...even with burning perfectly normally and just a light coat of fly ash on everything, I (and others) notice a difference in plenum temps vs exhaust temps right after cleaning...I try to clean 2-3 times per heating season. (you will notice exhaust temps drop, and plenum temps go up)


I have had it for two months. I cleaned it a month ago just to make sure it was a ok.


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## bropp (Jan 19, 2020)

woodey said:


> What temp do you have your lower limit switch set at and any thoughts from Brenn and JR about the placement of the switch?


I tried the switch in three places. The first switch was defective from the factory, which caused a lot of frustrating from the beginning.  It's currently high in the plenum. I've played around with all the different temps and found 103 to be best.


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## bropp (Jan 19, 2020)

What would really help me is the following:
What temperature is measured in the plenum one foot or so above the furnace if the fan is on low, fire is at maximum heat setting and full burn, and intake air is around 60.

When I touch the plenum it feels cool. They told me to insulate it and all the ductwork, but it's not like the very well insulated garage is hot.
Another thing- I have a Well Connect open loop Geo unit. It produces 13500 btu. I have been playing around with it some days and it will keep the house (basement, garage) WARMER than the Kuuma. So to me the Kumma won't even produce 13k btu wide open.
I think it's defective.


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## brenndatomu (Jan 19, 2020)

bropp said:


> What temperature is measured in the plenum one foot or so above the furnace if the fan is on low, fire is at maximum heat setting and full burn, and intake air is around 60.


Where at specifically? Front, side, toward the back? The front should be hotter than the back.
This may be a hail mary...but is there any chance the blower is wired wrong...as in the wrong speed taps hooked up?



			https://www.lamppakuuma.com/wp-content/uploads/2018/10/VF100-Electrical-diagram.pdf


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## Woodman1 (Jan 19, 2020)

Is there a formula for measuring output from temperature rise from a forced air furnace? Something like cfm*rise?? I would think if there is it would save a lot of frustration by ruling things out. I know with a boiler it's the simple formula of gpm*500*delta t through the boiler. A quick glance at the temp gauge gives me a pretty good idea of what my boiler is doing.


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## SpaceBus (Jan 19, 2020)

I think 75df register temp is the issue. Perhaps there is a ductwork issue.


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## brenndatomu (Jan 19, 2020)

SpaceBus said:


> I think 75df register temp is the issue. Perhaps there is a ductwork issue.


Return air temp is a little low (but so is house temp) supply air is low...so register temps will be low too...but supply ducts running through a cold space is not going to help any...not sure if this basement garage is cold or not...something is off here for sure though...but I really doubt it is the furnace...my money is on something in the setup...this thing should be roasting them clean out of the house...or at least having the wife shedding layers of clothes!


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## hobbyheater (Jan 22, 2020)

bropp said:


> Dale said the inside flue temp should be around 225-275 and no more. I've had the barometric set every which way with nothing but cresote one way and a shorter burn the other. The cold air return is ducted right into the box. It doesn't take in hardly any basement air, I even taped it tight. I've talked to Dale and tried the baffles every which way and run the want every which way too.


  Have you tried running without the barometric damper ?


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## Highbeam (Jan 22, 2020)

bropp said:


> Dale said the inside flue temp should be around 225-275 and no more.



I betcha he meant the outside of the interior (aka inside) pipe should be 225-275. Not the inside of the inside pipe.


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## bropp (Jan 25, 2020)

I've tried something different this week and found an unusual result- I've had the computer on the lowest setting and it has warmed the house significantly. It got up to 65 degrees. It has been 30 out, about the same as it's been all winter.  Yesterday there was a power outage and a cracked the damper open with a screwdriver. Without the fan running the house got to 67.  Why would my house be so much colder with the furnace on the highest setting? I don't have it backwards and I'm not letting it burn down too much on high.


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## brenndatomu (Jan 25, 2020)

Yeah, doesn't make any sense, does it?!
@JRHAWK9  found the same thing in regards to slowing the blower down heats his house better...not to the point of zero, like you had during the power outage, but still way slower than normal low speed...which is accomplished with some aftermarket controls.
As for why running the burn rate on low works better than high...you got me...unless your chimney draft is too high? That might make some sense...maybe?
Where is your draft set now? How are you checking it exactly, have any pics of that setup? I don't recall seeing where on the stove pipe you are connected in for the Dwyer...


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## gary38532 (Jan 25, 2020)

bropp said:


> For the last five years I've been reading great things about the vf100 and have been wanting one. I finally purchased one and am very disappointed- I can't get it to heat my house!  The firebox is a blast furnace but the plenum feels cool. I don't know why the heat won't leave the firebox. I  can't get my house above 60 and its in the upper 50s in the morning and it's been super warm outside- lows 20 above and highs close to thirty! I  have a thermometer on the registers and usually reads 72. I don't know how to get more heat from it. I insulated the plenum and put a probe in one foot above the plenum- when the furnace is roaring on the highest setting it reads 90 degrees.
> 
> I live in a 3000 sq ft house with two garage doors in the lower level. It is essentially a 1500 sq ft ranch with a Wood walled 2x6 walkout basement. The entire thing has r19 walls. The garage doors are insulated and plugged around the edges, I don't use them.  House was built in 94 and has good insulation .
> I've been burning wood my entire life. I am burning dry Ash and maple between 15-20 percent on the moisture meter.
> ...


Thank god for your post so I know im not going crazy! mine is the same by all accounts... you should read my post... its long but I want to send mine back too





						new Vapor Fire 100 with very poor heat
					

I heated my 2800 sqft home with a old Clayton 1800 for the last 6 year here in northern PA. It always did a very good job keeping the house 75 even on the coldest January nights. The only problem was it went through about 9 cords of wood and dirty the chimney all the time. After reading all the...




					www.hearth.com


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## motoguy (Jan 27, 2020)

Our house is approx 3800 sq ft, 1900 up and 1900 down, tall vaulted ceilings upstairs, ~10ft ceilings downstairs.  Downstairs is a walkout basement, 3 of the walls are concrete and earth-contact.  Lots of cubic feet to heat, and the concrete is always trying to suck the heat out of the walls.

Here are some photos of our installation.  Flue setup is similar to your.  Our VF100 provides 100% of our heat down to the high-teens outdoor temp.  At that point, we have to kick on the propane furnace for assist.  We like to keep it 68 or above.  If it's above 40 outside, I don't even fire up the Kuuma, as even on the "low" setting (and pot at low) it gets too hot inside.

Assuming the home is sealed/insulated, the Kuuma should have more than enough heat for the the OP's home.  Tag to come back and read completely.

ETA:  This is the first year for the return duct.  The previous several years, we've just had the blower box open to the room.  We added the wall for the "furnace room" last year.  Knowing the room will be closed eventually, we added the return air ductwork.  It feeds from the top of the furnace room wall, which is a family room.


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## motoguy (Jan 27, 2020)

brenndatomu said:


> Your draft should be -0.04" to -0.06"...I usually run around -0.045"...



I usually run on the .06" side of things.  Are there any benefits/reasons to lean towards the .04" side of things?   Longer burn times, I suppose?


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## motoguy (Jan 27, 2020)

brenndatomu said:


> OK, that answers one of my original questions...how long have you been using it?
> Have you cleaned your heat exchanger area yet? If you had any crappy wood in that time (especially early on) it could have put a coat of crude on everything and it doesn't take much to start losing heat exchange efficiency...even with burning perfectly normally and just a light coat of fly ash on everything, I (and others) notice a difference in plenum temps vs exhaust temps right after cleaning...I try to clean 2-3 times per heating season. (you will notice exhaust temps drop, and plenum temps go up)



Hmmm...I usually clean my exchanger at the start of each heating season, and not again until the next.  This is good info.  If a warm day comes up where I let the fire go out, perhaps I'll check the exchanger tubes again.


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## brenndatomu (Jan 27, 2020)

motoguy said:


> I usually run on the .06" side of things.  Are there any benefits/reasons to lean towards the .04" side of things?   Longer burn times, I suppose?


Yeah a little, but the supply plenum temps can be a bit lower too...so you either need to turn the computer up, or bump the draft up when colder weather comes.


motoguy said:


> Hmmm...I usually clean my exchanger at the start of each heating season, and not again until the next.  This is good info.  If a warm day comes up where I let the fire go out, perhaps I'll check the exchanger tubes again.


Not something that has to be done obviously, but for someone that is pushing the limits of the VF100, cleaning the HX every couple months (or cords) can make a bit of difference, especially right after it is done. 
I'll do it if I have time during a warm spell, if not, meh...


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## motoguy (Jan 27, 2020)

brenndatomu said:


> Yeah a little, but the supply plenum temps can be a bit lower too...so you either need to turn the computer up, or bump the draft up when colder weather comes.
> 
> Not something that has to be done obviously, but for someone that is pushing the limits of the VF100, cleaning the HX every couple months (or cords) can make a bit of difference, especially right after it is done.
> I'll do it if I have time during a warm spell, if not, meh...



Got it.  We're already slightly outside the capabilities of the Kuuma, so I'll likely leave the draft where it is.  I'll turn the temp knob and pot down when it's warmer out, but turn both up when it's cold.  Knob all the way up, pot all the way up, everything full blast...I still have to supplement with propane once we hit the high teens ambient temps.


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## brenndatomu (Jan 27, 2020)

motoguy said:


> I still have to supplement with propane once we hit the high teens ambient temps.


Still takes a huge bite out of the yearly LP bill, eh?!
The last few years were 100% wood heat here...but finally got things situated the way I want this past summer, and that allows for using some fuel oil heat when the weather is really just too warm to fool with building a small fire once every day or two. I have a small stove in the living room fireplace that can work for those warmer spring and fall days too...or if we just want some "fire TV"


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## gary38532 (Jan 28, 2020)

motoguy said:


> We like to keep it 68 or above


Maybe it's perspective on what we think is warm I consider 68 cold. I like to keep the house like 73-74. It's hard/almost not possible to go that high with my Kumma. In its current state it can do 68, no problem.


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## brenndatomu (Jan 28, 2020)

gary38532 said:


> Maybe it's perspective on what we think is warm I consider 68 cold. I like to keep the house like 73-74. It's hard/almost not possible to go that high with my Kumma. In its current state it can do 68, no problem.


Agreed!
68* was the daytime setpoint when we had oil heat only...always felt cold to me...now with wood heat if we came home and found the house down to 68* it would be all hands on deck to get the fire stoked up again!


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## motoguy (Jan 28, 2020)

brenndatomu said:


> Agreed!
> 68* was the daytime setpoint when we had oil heat only...always felt cold to me...now with wood heat if we came home and found the house down to 68* it would be all hands on deck to get the fire stoked up again!



Ha!  It's 71 in here now, and I'm a bit on the warm side.  The few times we've accidentally got it to 73-74, the wife is complaining about it being too hot to sleep, sweating, etc.  At that point we usually open some windows to cool it down a bit. Then again, 68 on propane has a different "feel" than 68 on wood.  The wood heat is more comfortable. 

This coming from the guy that grew up in a house that was in the 80's during winter.  I remember my friends coming over to pick me up one night, and refusing to come in because it was in the 90s.  Middle of winter, and we'd be running around the house shirtless in our tightly whiteys, with front and back door open...


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## motoguy (Jan 28, 2020)

brenndatomu said:


> Still takes a huge bite out of the yearly LP bill, eh?!



Certainly!  The house came with a small Avalon Arbor (same as Lopi Leti, I believe) EPA stove.  The 2nd year in the house, we used this stove to burn some trees I had cleared on the property.  This little stove was rated for something like 2k sq feet...approx 1/2 the size of the house.  We were AMAZED at the reduction in propane usage, as well as the increased comfort in the upstairs (tile) floor...due to the heat rising from below.

The things we learned with Avalon played a part in the decision to drop the "big bucks" on the Kuuma.


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## brenndatomu (Jan 28, 2020)

Just ran across this, thought it was interesting...


			https://www.woodstove.com/images/pdffiles/PDF%20Article%20Downloads/BasementInstall.pdf


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## gary38532 (Jan 28, 2020)

brenndatomu said:


> Agreed!
> 68* was the daytime setpoint when we had oil heat only...always felt cold to me...now with wood heat if we came home and found the house down to 68* it would be all hands on deck to get the fire stoked up again!


same here


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## motoguy (Jan 28, 2020)

brenndatomu said:


> Just ran across this, thought it was interesting...
> 
> 
> https://www.woodstove.com/images/pdffiles/PDF%20Article%20Downloads/BasementInstall.pdf



Holy cow!  Wow, I guess I should look at insulating those exposed walls!


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## gary38532 (Jan 28, 2020)

brenndatomu said:


> Just ran across this, thought it was interesting...
> 
> 
> https://www.woodstove.com/images/pdffiles/PDF%20Article%20Downloads/BasementInstall.pdf


Would this be the same with a VF100 though because they are not heating the basement up like a wood stove would. Very little heat goes into my basement off mine. If I had returns (wish I did) I bet there would be almost no heat downstairs.


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## Spanky (Jan 28, 2020)

Hard to believe that your basement doesn't heat up from that Kuuma.   We have had ours 4 years now.  Home is a
1700 sq ft ranch built in 77.   We have a walkout type garage in the basement where I located the furnace.   Basement walls 
are cinder block in that area.   Zero insulation.   My temps run consistently above 80  degrees in the basement.   I have never had to turn the computer setting above low since I have run the furnace.   Our temps are almost always 68 to 71.   Any 
warmer and the wife starts disrobing.  Lol.   Just love the furnace and really try to have a good supply of dry wood.


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## gary38532 (Jan 28, 2020)

Spanky said:


> Hard to believe that your basement doesn't heat up from that Kuuma.   We have had ours 4 years now.  Home is a
> 1700 sq ft ranch built in 77.   We have a walkout type garage in the basement where I located the furnace.   Basement walls
> are cinder block in that area.   Zero insulation.   My temps run consistently above 80  degrees in the basement.   I have never had to turn the computer setting above low since I have run the furnace.   Our temps are almost always 68 to 71.   Any
> warmer and the wife starts disrobing.  Lol.   Just love the furnace and really try to have a good supply of dry wood.


so wait? its warmer in your basement then upstairs...


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## brenndatomu (Jan 28, 2020)

gary38532 said:


> Would this be the same with a VF100 though because they are not heating the basement up like a wood stove would. Very little heat goes into my basement off mine. If I had returns (wish I did) I bet there would be almost no heat downstairs.


If there were returns hooked up then basement temp wouldn't affect things much at all...other than your floor being a little cold maybe...


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## gary38532 (Jan 28, 2020)

brenndatomu said:


> If there were returns hooked up then basement temp wouldn't affect things much at all...other than your floor being a little cold maybe...


yes that's what im getting it at


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## brenndatomu (Jan 28, 2020)

Spanky said:


> Our temps are almost always 68 to 71. Any
> warmer and the wife starts disrobing.


So whats the problem then?!


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## motoguy (Jan 28, 2020)

Our downstairs holds a noticeable amount of heat from the Kuuma.  We don't have any registers open in the downstairs.  However, it is very open, and unfinished.


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## gary38532 (Jan 28, 2020)

motoguy said:


> Our downstairs holds a noticeable amount of heat from the Kuuma.  We don't have any registers open in the downstairs.  However, it is very open, and unfinished.


I didn't mean to imply that the basement is cold. It's just the upstairs is noticeably warmer. The lamppas say thats what they shoot for. They want to heat the upstairs not the downstairs. Unless you were to purposely blow hot air in there of course.


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## Spanky (Jan 29, 2020)

Yes it is warmer in the basement.   But that is where the Furnace is located.   Basically you have a firebox that
is radiating all kinds of warmth.   Now I am sure we could get it warmer upstairs if we wanted to but we are
very comfortable with it on the lowest setting.   I did turn it up to medium last year when we went through that
cold stretch of minus degree weather.   Here is a photo of the temps in the house last night.  This was taken after
letting the furnace cycle down probably 5 times and be just about time for my reload for the night.


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## gary38532 (Jan 29, 2020)

Spanky said:


> Yes it is warmer in the basement.   But that is where the Furnace is located.   Basically you have a firebox that
> is radiating all kinds of warmth.   Now I am sure we could get it warmer upstairs if we wanted to but we are
> very comfortable with it on the lowest setting.   I did turn it up to medium last year when we went through that
> cold stretch of minus degree weather.   Here is a photo of the temps in the house last night.  This was taken after
> ...


Mines very consistent throughout the whole place about 70-72 incudling the basement. I have no returns so it probably mixing it up good.


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## Spanky (Jan 29, 2020)

Our living room has always run a couple degrees cooler in the winter.   It's located at the complete opposite end of 
a long ranch style home that the furnace is at.   It also has tall vaulted ceilings.   But it sounds like your starting to get things
worked out on your system, which is good.   I actually have picked up some worthwhile tips from your thread for future insulating ideas.


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## gary38532 (Jan 29, 2020)

Spanky said:


> Our living room has always run a couple degrees cooler in the winter.   It's located at the complete opposite end of
> a long ranch style home that the furnace is at.   It also has tall vaulted ceilings.   But it sounds like your starting to get things
> worked out on your system, which is good.   I actually have picked up some worthwhile tips from your thread for future insulating ideas.


It's been warm all week in the lower 30s. I have to use the electric under 20.


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## JRHAWK9 (Feb 11, 2020)

Here is the situation we have our Kuuma VF100 heating.  

We got 9" of snow on Sunday.  After I blew the driveway, I snapped these photos only a couple hours after it stopped snowing.  Was 22° outside.  There is supposed to be 9" of snow on the roof.  Garage pic as a reference, as it's not heated.  Front and back roof of the house.  Losing a lot of heat along the whole length of roof peak.  Our indoor humidity levels are also low..........but the house is warm.

Front of house:




Rear of house:



Garage:


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## Gbawol42 (Feb 11, 2020)

JRHAWK9 said:


> Here is the situation we have our Kuuma VF100 heating.
> 
> We got 9" of snow on Sunday.  After I blew the driveway, I snapped these photos only a couple hours after it stopped snowing.  Was 22° outside.  There is supposed to be 9" of snow on the roof.  Garage pic as a reference, as it's not heated.  Front and back roof of the house.  Losing a lot of heat along the whole length of roof peak.  Our indoor humidity levels are also low..........but the house is warm.
> 
> ...



I'm still honestly surprised your heating as many square feet as you are, with that much heat loss.  Posts like this make me feel excited about the future when I get my house and furnace dialed in better.


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## JRHAWK9 (Feb 11, 2020)

Gbawol42 said:


> I'm still honestly surprised your heating as many square feet as you are, with that much heat loss.  Posts like this make me feel excited about the future when I get my house and furnace dialed in better.



We don't have a very large house, square footage wise, but do have a fairly decent amount of volume based on the footprint.  It's a 32'x42' footprint, but around 32,000CF including the basement.  The basement is heated solely off of the radiant from the Kuuma.  The 1/3 of it where the furnaces are stay right around the same as the rest of the house, the other 2/3rds  of it is a bit cooler.


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## brenndatomu (Feb 22, 2020)

Any updates here @bropp ?


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## BaseheartsUSA (Dec 18, 2022)

Unfortunately, I am having the same issues with my new Kuuma Vapor 100...I've had this thing hooked up and operating for about 3 months now...Professional HVAC company installed and ducted..the whole 9 yards...a big production....I'm in Tennessee, so VERY mild winter weather.  The Kuuma operates and heats the house GREAT when outdoor temps are in the 40s...When outdoor temps  drop into the mid 30s, the Kuuma still keeps the house "kind of warm" at about 67 degrees..Yes, that's with the firebox blazing away... I researched wood burning furnaces for over 2 years, and carefully decided the Kuuma was the way to go...This was a VERY big investment for my family.  My house is 1900 Sq. Ft. one story living space, ranch style house with a full basement. Nothing exotic. Big tall chimney as well.  Oh yea, the Kuuma itself operates as advertised..Stack a bunch of nice seasoned hard wood in the fire box, and it gets HOT! The problem is, this heat is not transferring into nice warm air in the house..Today, the temp outside is 26 degrees (I know, 26 degrees is child's play compared to all of you in the Northern regions and Canada)  but for Tennessee that's cold And the Kuuma still can't get my living space above 64 degrees  I "guess" it's the fan moving the air too quickly past the heating area just below the plenum because cold air is blowing through my floor vents...It's embarrassing quite frankly....  I know the stove pipe is hooked up correctly and the smoke runs out the chimney clear as glass, so even if this thing needs to be adjusted here and there, I do not see how I will ever get consistent 70 degree indoor heat from it..I just don't think it will happen.  I can't find any reason why this thing can't produce heat in my house above 64 degrees on a day when it's 26 degrees outside....I guess (when I get the time to deal with it) I'll have the HVAC guys come out AGAIN to scratch their heads and offer little solutions...I do feel like to a large degree I have a very expensive paperweight that will at least keep us from freezing to death if the grid goes down...Word of advice, I just feel there are too many variables involved when trying to heat a home with a wood burning furnace...there are too many variables to take the gamble if you're  looking to heat a home with this thing and no house/chimney/draft/ducting etc. are created equal.  Results WILL vary from house to house for certain with these furnaces and that is VERY problematic.  I know the folks that are getting 77 degrees inside their houses when the temps outside are below 0 are telling the truth..I trust the folks at Kuuma 100%, but man, this was a big expense and I'm just wasting beautiful firewood at this point.  Thank God I still have my heat pump on my HVAC unit and propane set up. Serious advice: If you really are dead set on burning wood for heat, set up the cheapest unit you can, see how it works for you. If you like the results, many then after a few years of saving money, look at getting a Kuuma...maybe you'll have those excellent results all of us read about from satisficed customers...Maybe your house/chimney/ducting, and all the science that goes into this just works for you and your house.  Thanks


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## JRHAWK9 (Dec 18, 2022)

BaseheartsUSA said:


> Unfortunately, I am having the same issues with my new Kuuma Vapor 100...I've had this thing hooked up and operating for about 3 months now...Professional HVAC company installed and ducted..the whole 9 yards...a big production....I'm in Tennessee, so VERY mild winter weather.  The Kuuma operates and heats the house GREAT when outdoor temps are in the 40s...When outdoor temps  drop into the mid 30s, the Kuuma still keeps the house "kind of warm" at about 67 degrees..Yes, that's with the firebox blazing away... I researched wood burning furnaces for over 2 years, and carefully decided the Kuuma was the way to go...This was a VERY big investment for my family.  My house is 1900 Sq. Ft. one story living space, ranch style house with a full basement. Nothing exotic. Big tall chimney as well.  Oh yea, the Kuuma itself operates as advertised..Stack a bunch of nice seasoned hard wood in the fire box, and it gets HOT! The problem is, this heat is not transferring into nice warm air in the house..Today, the temp outside is 26 degrees (I know, 26 degrees is child's play compared to all of you in the Northern regions and Canada)  but for Tennessee that's cold And the Kuuma still can't get my living space above 64 degrees  I "guess" it's the fan moving the air too quickly past the heating area just below the plenum because cold air is blowing through my floor vents...It's embarrassing quite frankly....  I know the stove pipe is hooked up correctly and the smoke runs out the chimney clear as glass, so even if this thing needs to be adjusted here and there, I do not see how I will ever get consistent 70 degree indoor heat from it..I just don't think it will happen.  I can't find any reason why this thing can't produce heat in my house above 64 degrees on a day when it's 26 degrees outside....I guess (when I get the time to deal with it) I'll have the HVAC guys come out AGAIN to scratch their heads and offer little solutions...I do feel like to a large degree I have a very expensive paperweight that will at least keep us from freezing to death if the grid goes down...Word of advice, I just feel there are too many variables involved when trying to heat a home with a wood burning furnace...there are too many variables to take the gamble if you're  looking to heat a home with this thing and no house/chimney/draft/ducting etc. are created equal.  Results WILL vary from house to house for certain with these furnaces and that is VERY problematic.  I know the folks that are getting 77 degrees inside their houses when the temps outside are below 0 are telling the truth..I trust the folks at Kuuma 100%, but man, this was a big expense and I'm just wasting beautiful firewood at this point.  Thank God I still have my heat pump on my HVAC unit and propane set up. Serious advice: If you really are dead set on burning wood for heat, set up the cheapest unit you can, see how it works for you. If you like the results, many then after a few years of saving money, look at getting a Kuuma...maybe you'll have those excellent results all of us read about from satisficed customers...Maybe your house/chimney/ducting, and all the science that goes into this just works for you and your house.  Thanks


I would concentrate on your cold air and supply air.  The results I am seeing now are much better than they were before I tweaked the airflow through the furnace.  In my case I slowed  the air flow down drastically.  I also increased my return air temp.  You are right though, there is not a one setup that fits for all situations.  

Would be curious to know your return air temps as well as your supply temps at the plenum.


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## brenndatomu (Dec 18, 2022)

BaseheartsUSA said:


> Unfortunately, I am having the same issues with my new Kuuma Vapor 100...I've had this thing hooked up and operating for about 3 months now...Professional HVAC company installed and ducted..the whole 9 yards...a big production....I'm in Tennessee, so VERY mild winter weather.  The Kuuma operates and heats the house GREAT when outdoor temps are in the 40s...When outdoor temps  drop into the mid 30s, the Kuuma still keeps the house "kind of warm" at about 67 degrees..Yes, that's with the firebox blazing away... I researched wood burning furnaces for over 2 years, and carefully decided the Kuuma was the way to go...This was a VERY big investment for my family.  My house is 1900 Sq. Ft. one story living space, ranch style house with a full basement. Nothing exotic. Big tall chimney as well.  Oh yea, the Kuuma itself operates as advertised..Stack a bunch of nice seasoned hard wood in the fire box, and it gets HOT! The problem is, this heat is not transferring into nice warm air in the house..Today, the temp outside is 26 degrees (I know, 26 degrees is child's play compared to all of you in the Northern regions and Canada)  but for Tennessee that's cold And the Kuuma still can't get my living space above 64 degrees  I "guess" it's the fan moving the air too quickly past the heating area just below the plenum because cold air is blowing through my floor vents...It's embarrassing quite frankly....  I know the stove pipe is hooked up correctly and the smoke runs out the chimney clear as glass, so even if this thing needs to be adjusted here and there, I do not see how I will ever get consistent 70 degree indoor heat from it..I just don't think it will happen.  I can't find any reason why this thing can't produce heat in my house above 64 degrees on a day when it's 26 degrees outside....I guess (when I get the time to deal with it) I'll have the HVAC guys come out AGAIN to scratch their heads and offer little solutions...I do feel like to a large degree I have a very expensive paperweight that will at least keep us from freezing to death if the grid goes down...Word of advice, I just feel there are too many variables involved when trying to heat a home with a wood burning furnace...there are too many variables to take the gamble if you're  looking to heat a home with this thing and no house/chimney/draft/ducting etc. are created equal.  Results WILL vary from house to house for certain with these furnaces and that is VERY problematic.  I know the folks that are getting 77 degrees inside their houses when the temps outside are below 0 are telling the truth..I trust the folks at Kuuma 100%, but man, this was a big expense and I'm just wasting beautiful firewood at this point.  Thank God I still have my heat pump on my HVAC unit and propane set up. Serious advice: If you really are dead set on burning wood for heat, set up the cheapest unit you can, see how it works for you. If you like the results, many then after a few years of saving money, look at getting a Kuuma...maybe you'll have those excellent results all of us read about from satisficed customers...Maybe your house/chimney/ducting, and all the science that goes into this just works for you and your house.  Thanks


I'm gonna throw a few questions at you here...
Have you had your HVAC guys out to look things over again?
Have they talked with Lamppa?
Most HVAC people treat wood furnaces like a gas furnace (the ones that will even mess with them at all) but they are two very different machines! Most HVAC guys are totally clueless when it comes to tweaking things and setting up a wood furnace to work properly...and half the ones that think they know, really don't...there is a lot of misinformation out there in regards to heating with wood.
Have you checked to see that the baffles are in place in the HX? That will make a big difference.
What is your draft set at, you said you have a very tall chimney, that often means high draft, which mean a ton of heat lost up the chimney...you need to get a draft reading and make sure your baro is working, and set right...some people that have tall chimneys actually need two dampers. Do yourself a favor and buy a Dwyer Mark II model 25 manometer to leave hooked up all the time...they are not expensive and provide valuable info...I look at mine everyday. Oh, also need chimney type and specs.
Do you have you return air ducts hooked up, or just pulling basement air in?
Often times the air at the floor is 10* lower than the air at the ceiling...just hooking up the return air ducts means the furnace can add temp rise (often in the 40* range) to room temp air (64* in your case right now) instead of basement temp air which is what, low to mid 50's?
Are your supply ducts insulated?
Are you using the thermostat...in other words, is the blower running on high, or low? I find running the blower on high (tstat calling for heat) to be just about worthless.
I assume you are using the filters that the VF came with?
How big was your previous furnace, and how much fuel did you use per year (gas/oil/electric?) In other words, what is your heat load like/how well is your house insulated/air sealed?
Don't lose hope, its sounds like you are on the right track, and believe it or not, once you get things dialed in the VF will heat you plumb outta the house!


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## brenndatomu (Dec 18, 2022)

BaseheartsUSA said:


> Unfortunately, I am having the same issues with my new Kuuma Vapor 100


And just FYI, here is an update that the OP of this thread posted the following year...





						Kuuma VF 100
					

Last year I had a VF 100 and was unhappy with the amount of heat it produced. It was not heating my house. I got a Fire Chief 1700 instead. The FC did produce a little more heat, but that was when I feed it 4x as much wood.  Not only that, even though I would feed it a ton right before bed the...




					www.hearth.com
				




Also, have you tested the moisture content of your wood by splitting open room temperature wood and then probing the middle of the freshly exposed faces? Burning wood that is not really dry wastes a lot of BTU's up the chimney and might explain why it was able to keep up in warmer weather, but not now...I know Lamppa claims the VF can burn wood that is 18-28% MC, but my experience has been that wood much over 20% just plain makes less heat...and some burn wood with quite a bit lower MC with great results.
It would be more obvious if the wood was too wet in a manually controlled stove, but with the VF and its auto controlled damper it will burn just about any wood to a fine white ash...just makes less heat doing so.
What species are you burning? Has it been CSS'd (cut/split/stacked) for a couple years?


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## brenndatomu (Dec 19, 2022)

One more thought...does your blower stay on almost all the time when there is a fire? It should...if not you may have a bad low limit switch...
(that's assuming the blower is running on low speed)



> Serious advice: If you really are dead set on burning wood for heat, set up the cheapest unit you can, see how it works for you. If you like the results, many then after a few years of saving money, look at getting a Kuuma.


Bad advice...look around on here for the results of people that have bought the current generation of elcheapo big box store wood furnaces...bad results! You'd be better off buying a nice used unit of a model no longer made...there are a few good ones out there.
But whatever you do, all wood furnaces will have to be setup properly to do the job well...unless maybe you buy something that is WAY oversized, and then you'll use way too much wood, and the house will be too hot when the weather is mild (most of the time in Tenn.)


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## BaseheartsUSA (Dec 19, 2022)

JRHAWK9 said:


> I would concentrate on your cold air and supply air.  The results I am seeing now are much better than they were before I tweaked the airflow through the furnace.  In my case I slowed  the air flow down drastically.  I also increased my return air temp.  You are right though, there is not a one setup that fits for all situations.
> 
> Would be curious to know your return air temps as well as your supply temps at the plenum.


Hi JRHAWK9! Thanks for the message.  Oh yea, that's the big project I'm undertaking soon..At present, I am pulling the cold air from the concrete floor of my unfinished drafty basement, so that is an issue for sure.  Please tell me, now that you have tweaked the airflow through your furnace, are you able to get your living space AT LEAST  up to 68 degrees consistently even when the outdoor temps are as low as around 14 degrees and up into the mid 20s degree range?  If I can get my Kuuma to heat my living space at a consistent 68 degrees, I will be a winner because we actually like the house at 68 degrees in winter.   What steps did you take to achieve your new results?  I was told to run an open, vertical box from the back of the blower/filter housing area up to my floor joists in the basement...I'm actually thinking of running some custom stove pipes from the back of the blower/filter housing horizontally  along the side of the unit with a bend that actually touches the top of the front door seam area of the firebox...the air around the firebox door is HOT, so I'm planning to try to set something like that up.  Something where I can lift up the tubbing a bit when I need to open the door, then lower back in place when I have the unit running drawing that hot air from the furnace door area.  I've actually seen a picture on the Kuma website of a customer that did this. The posting was recent on November 22nd 2022.. I would think the temps of the air right there at the top of the furnace door when it's in operation are in excess of 150 degrees.  If so, I would hope this 150 or more degree air would translate into maybe 90 degree air once it hits the bower, then maybe once it crosses over the heated area just below the plenum remains at around 90 degrees, then when it hits my vents in the house, I'm hoping for maybe 75 degrees, then at least 68 degrees as the warm air fills the house.  Any info you could share is greatly appreciated!


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## BaseheartsUSA (Dec 19, 2022)

brenndatomu said:


> I'm gonna throw a few questions at you here...
> Have you had your HVAC guys out to look things over again?
> Have they talked with Lamppa?
> Most HVAC people treat wood furnaces like a gas furnace (the ones that will even mess with them at all) but they are two very different machines! Most HVAC guys are totally clueless when it comes to tweaking things and setting up a wood furnace to work properly...and half the ones that think they know, really don't...there is a lot of misinformation out there in regards to heating with wood.
> ...


Thank you kindly for the message brenndatomu! What s- "baffles are in place in the HX" And YES, I figured out quickly the high limit blower setting is useless..I have the Honeywell thermostat set very low so the blower is running consistently and always at low speed...BTW, on one side of my house, I am getting heat out of the vents that is pretty warm..just about as warm as when my heatpump or propane are running..other vents are pretty cold. We are ordering the Dwyer today..I alread have that model you mentioned pulled up on Amazon. I had my barometric damper set at about 2 1/2 originally, and it would flap pretty consistently..I then read that to creat more heat in firebox, move damper dial closer to 5 so I have the damper set at about 4 1/2 right now and you only see it flap on occassion....Chimney is a 1930s in good shape with two flues.  One flue is for the fireplace in the living area and one flue is for a furnace...I would imagine a coal furnace was originally using the basement flue opening...Chimney is built on a huge, pretty amzing stone "stump" as they call it, brick inside of that, and it's beautiful...I have measured and from the basement up to the top of chimney is right at about 29 (no more than 31) feet from the base of the stump in the basement to the top of the crown of the chimney on the roof.  If you deduct the feet where the Kuuma stove pipe actually goes into the chimney stump in the basement, which is exactly 4 feet from the floor you get right about 27 feet of chimney being used.  so from where the Kuuma attaches to the chimney to the very top of my chimney, the length is right at about 27 feet, and certainly no more than 30 feet.  I do believe i've burned some not so well seasoned wood.  I am using all oak and hickory for firewood which I buck down and split with a splitter...I've allowed this  wood to season for approximately one year and I can tell the difference of when I use a well seasoned piece of wood in the Kuuma as opposed to a not so well piece of wood...you're right about that...this wood needs to be well seasoned. Actually, my HVAC guys built a solid fabricated box that extends out from the back that houses a solid filter..the fabricated metal box extends 10 inches from the back of the blower box and is 27X22 ..It has those two tabs I can push to open and replace the filter...the area size of this filter with the removable cover is 27x22...I had to do this because my stovepipe runs at about a 15 degree angle (The pipe dose NOT run horizontal, as I know this would be a real problem)  right above the back of the blower housing, and I'm unable to access the filters as Kuuma designed it because the stovepipe is in the way.   No supply ducts are installed.  I have two removable metal "sliders" installed in the duct work.  One I pull out when I run the Kuuma, and I close the other one off which cuts the air flow to my furnace.  When I run the furnace or AC, I close off the Kuuma by sliding one of these sliders in, then open up the bigger slider to let the furnace/AC work properly. The kuuma plenum is insolated, and th ducting (with that slider pulled out) only runs air throught the duct work that ends up pushing air through the vents in the house.  I have two big metal grate returns in the house with appropriate filters I replace as needed.  These returns do not have any Kuuma airflow passing by them..those returns only operate when I have the furnace/ac running and again, make sure i have the sliders adjusted accordingly.


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## sloeffle (Dec 19, 2022)

BaseheartsUSA said:


> the air around the firebox door is HOT, so I'm planning to try to set something like that up.  Something where I can lift up the tubbing a bit when I need to open the door, then lower back in place when I have the unit running drawing that hot air from the furnace door area.  I've actually seen a picture on the Kuma website of a customer that did this. The posting was recent on November 22nd 2022.. I would think the temps of the air right there at the top of the furnace door when it's in operation are in excess of 150 degrees.  If so, I would hope this 150 or more degree air would translate into maybe 90 degree air once it hits the bower, then maybe once it crosses over the heated area just below the plenum remains at around 90 degrees, then when it hits my vents in the house, I'm hoping for maybe 75 degrees, then at least 68 degrees as the warm air fills the house.  Any info you could share is greatly appreciated!


That's a special edition wood furnace that's only available from Kuuma if you live in or near Wisconsin Dells, WI.


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## BaseheartsUSA (Dec 19, 2022)

sloeffle said:


> That's a special edition wood furnace that's only available from Kuuma if you live in or near Wisconsin Dells, WI.


Well, that system looks cool AND it looks like it would work to bring hot air into the blower box...Any ideas on how good setting those pipes up will be for bringing hot air to the blower?


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## JRHAWK9 (Dec 19, 2022)

I think you may have seen a photo of what I did to reclaim some of the radiant heat off of the face.  All I'm doing is simply increasing the delivered efficiency of the furnace.   

I'm taking my cold air off the basement ceiling as well by doing what you mentioned above.

It seems you simply are trying to heat cold basement air.  You may need to hook it up the home's return air system or find another way to increase the return air temps.  You need to see an accumulative effect on the house temp.  You won't see that if the air you are taking in is always, say, 55 degrees.  When you hook up your cold air returns, as the house warms up the return air warms up, then the house warms up more, then the cold air temp warms up more...etc.  you will not see that by simply trying to intake the same 55° basement air.

I have my own reasons why I could not and did not want to hook my return air up.


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## lampmfg (Dec 19, 2022)

I will have Dale look this over and follow up.  The issue is he's swamped.


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## BaseheartsUSA (Dec 19, 2022)

lampmfg said:


> I will have Dale look this over and follow up.  The issue is he's swamped.  The odds of the VF100 not being able to adequately heat that size of a house in TN when installed correctly is pretty tiny.


I agree 100% Garrett! The furnace works as advertised as I mentioned.  Just frustrating to be chasing items, but I feel confident if I can get warm (or even hot) air moving into the "cold air return" on the Kuuma, all will be well..


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## lampmfg (Dec 19, 2022)

Dan,
I read your original post and noted that you moved your barometric damper from 2 1/2 to 4 1/2 because the damper flap was flapping open.  By increasing the number to 4 1/2 you are increasing the draft "to the furnace" which in turn will draw more heat up the chimney.  I would probably go back to at least #3 since you have a fairly tall chimney.  Secondly, I wouldn't focus too much on whether the barometric damper flap is moving.  Sometimes it will be totally still (not moving) in a closed position, and other times it might be standing continually open( on windy days).  I agree that you may want to purchase a monometer to monitor your draft. 
I also agree that the biggest variable is the wood.  Lamppa recommends wood between 18 and 28% moisture because this is what the EPA says the furnace must be able to burn cleanly, and the furnace must be certified to these moisture readings.  But actually around 14% up to around a high of around 24% seems to be optimal.  I did notice that last year when our wood was at only 8% moisture we only got around 5 hours of burn time with the Kuuma.  But this year with the same furnace, same type of wood (birch), but at around 24% we consistently get around 13 hours.  I agree that wood that is higher in moisture (over 24%) will consume Btu's to drive the extra moisture off the wood.

When you load your furnace - does the furnace go down to a small "c" on the control?  With seasoned wood it will normally hit small "c" in anywhere from 15 minutes to 35 minutes.  Higher moisture wood may never hit small "c".
We also agree with the importance of your cold air return.  I know we call it cold air, but we want this air as warm as we can get it.  If you are drawing from the basement, try to draw the air from up above the blower.  If you attach to your home's cold air return - you may even want to insulate this cold air ducting.
I agree with everyone else, once you get this furnace tuned to your home, it should provide years and years of very comfortable heat.
Dale


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## woodey (Dec 19, 2022)

Just curious as to the size of the flue.


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## brenndatomu (Dec 19, 2022)

BaseheartsUSA said:


> What s- "baffles are in place in the HX"


The baffles in the top...that you have to remove to clean the HX...look it up in the manual, page 24
Just make sure they are properly in place.


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## burtman4 (Dec 20, 2022)

I am heating a similar setup.  Roughly 1900 sq ft ranch with full basement in Maryland.   It's 26 degrees here now and it's 72 inside with the VF100 on low right now.   The one difference is I have my complete HVAC return going through the VF100 so I can draw warmer conditioned air through the return to the VF100.   I have two Normally Open / Power Closed dampers with a set of relays to section it off from the my heat pump for backup when I need it.   My setup allowed me to duct both the heat pump and VF100 so they could share with the same ducts.    I think the others may be on to something with the cold air return as the rest of your setup appears similar to mine.    My house is built in 70's, so the insulation is average also.     I also quit using the thermostat on the VF100 a year or so ago, and just let the fan run on low all the time.   I feel it gives me more heat, but I can't really quantify that as I was warm either way.   The one thing it did do, is equalize the temperature in my house better.    I have cheap thermometers in each room and noticed a better balance in them when I started only running the fan on low.   Don't give up, you will get there.


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## BaseheartsUSA (Dec 20, 2022)

brenndatomu said:


> The baffles in the top...that you have to remove to clean the HX...look it up in the manual, page 24
> Just make sure they are properly in place.


Yep, those stainless steel baffles are installed correctly.  One is a rectangle box with fireproof insulation in it and the other is an angled piece of stainless metal


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## BaseheartsUSA (Dec 20, 2022)

burtman4 said:


> I am heating a similar setup.  Roughly 1900 sq ft ranch with full basement in Maryland.   It's 26 degrees here now and it's 72 inside with the VF100 on low right now.   The one difference is I have my complete HVAC return going through the VF100 so I can draw warmer conditioned air through the return to the VF100.   I have two Normally Open / Power Closed dampers with a set of relays to section it off from the my heat pump for backup when I need it.   My setup allowed me to duct both the heat pump and VF100 so they could share with the same ducts.    I think the others may be on to something with the cold air return as the rest of your setup appears similar to mine.    My house is built in 70's, so the insulation is average also.     I also quit using the thermostat on the VF100 a year or so ago, and just let the fan run on low all the time.   I feel it gives me more heat, but I can't really quantify that as I was warm either way.   The one thing it did do, is equalize the temperature in my house better.    I have cheap thermometers in each room and noticed a better balance in them when I started only running the fan on low.   Don't give up, you will get there.


Thanks Burtman4! Yep, I fell confident from all of the responses that once I get warm air running through the cold air return it will be fine..I figured out that high setting on the blower was useless pretty quickly....It clearly pushes the air too fast through the Kuuma and it definitely heats better on low...I keep my thermostat set really low  and that keeps that blower operating on low all of the time.


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## BaseheartsUSA (Dec 20, 2022)

lampmfg said:


> Dan,
> I read your original post and noted that you moved your barometric damper from 2 1/2 to 4 1/2 because the damper flap was flapping open.  By increasing the number to 4 1/2 you are increasing the draft "to the furnace" which in turn will draw more heat up the chimney.  I would probably go back to at least #3 since you have a fairly tall chimney.  Secondly, I wouldn't focus too much on whether the barometric damper flap is moving.  Sometimes it will be totally still (not moving) in a closed position, and other times it might be standing continually open( on windy days).  I agree that you may want to purchase a monometer to monitor your draft.
> I also agree that the biggest variable is the wood.  Lamppa recommends wood between 18 and 28% moisture because this is what the EPA says the furnace must be able to burn cleanly, and the furnace must be certified to these moisture readings.  But actually around 14% up to around a high of around 24% seems to be optimal.  I did notice that last year when our wood was at only 8% moisture we only got around 5 hours of burn time with the Kuuma.  But this year with the same furnace, same type of wood (birch), but at around 24% we consistently get around 13 hours.  I agree that wood that is higher in moisture (over 24%) will consume Btu's to drive the extra moisture off the wood.
> 
> ...


Thanks Dale! I do get the cold c every time I load the furnace with wood BUT I would feel very certain there are inconsistencies with some of my wood's moisture content levels.  As I cut, split and dry my wood in the future, I'll take care to get the wood where I need it.  This is my first season so some of the wood I have is 2 years of seasoning and some only one year.


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## brenndatomu (Dec 20, 2022)

I assume you have turned the computer up, not still running on low...? (although from what you describe you should be able to leave it on low once you get things sorted out...mine rarely leaves low, even up here in NE OH)


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## BaseheartsUSA (Dec 20, 2022)

brenndatomu said:


> I assume you have turned the computer up, not still running on low...? (although from what you describe you should be able to leave it on low once you get things sorted out...mine rarely leaves low, even up here in NE OH)


I set the computer dial on 1/2 or just a tick above 1/2 towards hot.


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## BaseheartsUSA (Dec 20, 2022)

BaseheartsUSA said:


> I set the computer dial on 1/2 or just a tick above 1/2 towards hot.


If I set the dial to the highest setting, I'll burn through the wood faster correct?


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## brenndatomu (Dec 20, 2022)

BaseheartsUSA said:


> If I set the dial to the highest setting, I'll burn through the wood faster correct?


Yes, more wood burnt = more heat.


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## JRHAWK9 (Dec 21, 2022)

BaseheartsUSA said:


> Please tell me, now that you have tweaked the airflow through your furnace, are you able to get your living space AT LEAST up to 68 degrees consistently even when the outdoor temps are as low as around 14 degrees and up into the mid 20s degree range?



yep!  It's actually 0° right now and the house is 73°.  




BaseheartsUSA said:


> What steps did you take to achieve your new results? I was told to run an open, vertical box from the back of the blower/filter housing area up to my floor joists in the basement...I'm actually thinking of running some custom stove pipes from the back of the blower/filter housing horizontally along the side of the unit with a bend that actually touches the top of the front door seam area of the firebox...the air around the firebox door is HOT, so I'm planning to try to set something like that up. Something where I can lift up the tubbing a bit when I need to open the door, then lower back in place when I have the unit running drawing that hot air from the furnace door area. I've actually seen a picture on the Kuma website of a customer that did this.



That's pretty much what I did, like I mentioned above.


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