Kuuma VF 100 not heating my house! Help!

[brenndatomu]

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...

 

[gary38532]

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

 

[brenndatomu]

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

So whats the problem then?!

 

[motoguy]

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.

 

[gary38532]

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.

 

[Spanky]

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.

 

[gary38532]

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.View attachment 256107

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

 

[Spanky]

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.

 

[gary38532]

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.

 

[JRHAWK9]

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:

 

[Gbawol42]

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:
View attachment 256869


Rear of house:
View attachment 256870

Garage:
View attachment 256871

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.

 

[JRHAWK9]

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.

 

[brenndatomu]

Any updates here @bropp ?

 

[BaseheartsUSA]

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

 

[JRHAWK9]

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.

 

[brenndatomu]

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!

 

[brenndatomu]

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?

 

[brenndatomu]

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.)

 

[BaseheartsUSA]

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!

 

[BaseheartsUSA]

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!

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.

 

[sloeffle]

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.

 

[BaseheartsUSA]

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?

 

[JRHAWK9]

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.

 

[lampmfg]

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

 

[BaseheartsUSA]

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..