Wood Furnace issues (Energy Mate)

[brenndatomu]

Yeah, you'll probably need to leave the key damper open this time of the year (temps too high outside) You may be able to close it a bit more in cold weather, but I'm not sure you really need it with your over-sized (likely) exterior chimney. The best thing to do would be to get a Dwyer Mark II manometer, hook it up to the pipe permanently, then you'll always know exactly what you draft is. You can find a used Dwyer Mark IIs on fleabay for $20 or so if ya watch for a bit, I have bought two like that.
EDIT (there are at least two candidates on there right now, just make sure you get one with the red gauge oil and the hoses included, unless it is really cheap, then you could get the hoses locally. Could just use any ole tubing, but FYI the oil is kinda pricey to buy by itself though.)

 

[j7art2]

Are they removable? As if when I need to replace the pipe?

I'm looking at their website. I don't even know what a manometer is. Obviously it measures draft, but since it's plastic, i don't see how it wouldn't melt. Lol

 

[brenndatomu]

You hook it to the pipe via the tubing. Get some small copper tubing that will slide snugly into the supplied Dwyer tubing, drill a hole into the flue pipe about halfway to the chimney (furnace side of the key damper) insert fore mentioned copper in the hole with a bend in it so that it "hangs" from the pipe, mount the gauge on a flat and level spot on the wall, BAM, you gots a draft reading!

 

[spirilis]

My own experience with woodstoves and exterior masonry chimneys... you can never damper it down "too far" since you have to feed heat to all that masonry in order to maintain draft, all while it's happily giving it up to the elements

I can imagine wood furnaces have the same issue in your situation.

 

[maple1]

Keep a real close eye on your chimney & creosote situation, until you get a handle on how to run it. Furnaces usually aren't as bad as boilers for that - but if your key damper moves on you & you don't notice (wind gusts can do that sometimes if it's loose in it's movement) you might get some buildup.

 

[maple1]

you can never damper it down "too far" since you have to feed heat to all that masonry in order to maintain draft, all while it's happily giving it up to the elements

Yes you can - then you get smoke in your house, as the OP has now found out.

But I might have misread what you were saying....

 

[j7art2]

Yes you can - then you get smoke in your house, as the OP has now found out.

But I might have misread what you were saying....

LOL very true. :D

That key damper is WIDE open after that incident.

My next question though, is there any way to make this thing more efficient? Like mentioned before, it does eat buckets and buckets of wood. It heats well (Got the house to 77 last night!! lol) but man, it mows through wood like a monster.

Can I use coal on these? just curious. Would be good for evenings.

 

[spirilis]

Yes you can - then you get smoke in your house, as the OP has now found out.

But I might have misread what you were saying....

Yes that was a misread, I meant you cannot (i.e. you shouldn't) damper it down too far -- or else you have problems (like smoke in the house)
Insulated liner in that chimney will be a massive breath of fresh air (just experienced that this fall, thank goodness!)

 

[maple1]

LOL very true. :D

That key damper is WIDE open after that incident.

My next question though, is there any way to make this thing more efficient? Like mentioned before, it does eat buckets and buckets of wood. It heats well (Got the house to 77 last night!! lol) but man, it mows through wood like a monster.

Can I use coal on these? just curious. Would be good for evenings.

Not sure on the coal - but I juggled a key damper on my old unit (a boiler) the whole time I had it (17 years). With that rig, it was a very fine line between keeping it open enough for good draft on the fire & a good burn, and closed enough so all the heat didn't go right up the stack. Throw in varying draft conditions from changing winds, and you could get to pulling your hair out. I also had a barometric damper, downstream of the key, that helped with the varying thing, and had a pretty good read on where to set it for my chimney after a lot of burning (which was right around the half-closed mark) - but there was still the odd occasion where I would get smoke in my basement because it was closed just a bit too much.

Do you have a barometric damper?

 

[j7art2]

Nope. Just the slider damper on the top of the loading door and the key damper in the pipe. I think my buddy has one of those barometric ones though on his high efficiency unit. Are those the ones that kind of 'blow in the wind'?

 

[j7art2]

I have another question guys. Does the limit switch control the draft blower at all on the front of the furnace?

It seems the toggle switch (circled in one picture with a yellow circle) is just an on/off. How do I control when it comes on? Either it's always on and I'm constantly having to adjust the tear drop for air intake, and I mow through wood like it's no one's business, or I turn it off. Isn't it supposed to turn off once the house reaches the temperature the thermostat is set at? I don't think it's doing it if so.

 

[brenndatomu]

Isn't it supposed to turn off once the house reaches the temperature the thermostat is set at? I don't think it's doing it if so

Yes, should be controlled by thermostat. The limit switch controls the duct blower only (well, it can shut the draft blower OFF if you hit the high limit temp)
That toggle switch should just be a manual ON, basically you can turn it ON regardless of what the thermostat is calling for.

 

[j7art2]

Hm.. okay. I just realized the thermostat was set to 74, not 70 like I thought. I'm going to raise it a few degrees and see if it shuts off.

I think one direction is simply off (i can't get it to turn on at all in one direction) and the other is on, but dependent on thermostat position. Like, if I flip the switch and the thermostat is set at 50, it won't turn on, but if the wife kicks it up (i tell her to cause I always forget when I go down to start a fire), it kicks on. I guess I answered my own question there in a way, but I've never seen it turn off from being too hot.

 

[brenndatomu]

I'm going to raise it a few degrees and see if it shuts off.

You mean lower it a few degrees?

but I've never seen it turn off from being too hot.

Something is not right if the thermostat never shuts the draft blower off even after being satisfied. I bet that thing will EAT some wood running like that! A lot of people quit using the draft blowers just because of high wood use. I did on my old furnace, just run it like a wood stove.

 

[j7art2]

I dont know that I can get it hot enough not to create tons of creosote if it's not blowing. The flue thermometer seems to only get hot enough to optimal burning range with the fan blowing.

Any suggestions? I mean, I guess I could just let it blow all the time and could just crack the teardrop to like 25% and just leave it there and hope for the best.

 

[brenndatomu]

Yeah, it is a balancing act with a forced draft furnace. I believe the design thinking is basically the creosote that was created during low fire will be burnt off when on high fire, therefore never building up enough to matter.

I mean, I guess I could just let it blow all the time and could just crack the teardrop to like 25% and just leave it there and hope for the best.

You wouldn't have any thermostat control that way....

 

[j7art2]

Good point. I still have yet to work out all of these little bugs yet between cutting wood for the season. (DNR firewood permit, I can get 5 full cords of seasoned wood dead and fallen in state land!)

Just traded my Mossberg 500 tactical shotgun for a Husqvarna 455 Rancher yesterday. That thing is a wood cutting beast. I wonder why it isn't shutting off. Or maybe the reverse, not turning on in 'off' mode.

 

[j7art2]

Oh! It did shut off. I guess the thermostats are just a few degrees off. The house is 75 (gag.. time to open a window) but the manual thermostat is only set to 70. Good to know I guess.

 

[brenndatomu]

I guess the thermostats are just a few degrees off.

Yup, that'll do it. My wood side thermostat reads about 1/2 degree cooler than the fuel oil side.
Just curious, what kind of thermostat do you have controlling this beast? Dial type? Digital programmable? My Yukon runs a Honeywell FocusPro 5000 'stat on the wood side, I really like it, very sensitive, great control. I think I gave $20 for it new on fleabay

 

[j7art2]

Yeah, old school dial. The other one is a digital Honeywell. Maybe I'll look at getting a digital. Just a simple digital one is $20. Didn't realize I could upgrade that one that easy, but I guess it makes sense.

 

[brenndatomu]

I think the normal retail price on the Focuspro 5000 is higher than $20 ($50?) I just found a new one somebody had leftover or something, wanted it out of the way. I really like it for a wood furnace though because it is so sensitive. It will maintain your setting without any variance in the displayed temp (unless you run outta wood ) I like it because it will run your draft blower for just short bursts to maintain temp instead of running the blower for longer trying to recover the lost 1 or two degrees span that your current thermostat likely has.
Example, on yours, set it at 70, 'stat starts blower at 69, shuts off at 71. Mine will do something like set it at 70, starts blower at 70, shuts off at 70.5, something like that, I dunno, like I said, the displayed temp just never moves if you have fuel in the fire. That keeps your fire hot but doesn't let the blower blast all the heat up the chimney by running too much.

 

[j7art2]

That actually sounds awesome and a lot more efficient. The one thing I don't like about my furnace is that it eats logs. Even with a well insulated house, I have a feeling that going through 3+ full cords a year is a real possibility.

If it allows for longer wood burns and less fuel on the fire (and thus less splitting, stacking and harvesting for me) then it's ultimately worth its weight in gold.

 

[maple1]

Even with a well insulated house, I have a feeling that going through 3+ full cords a year is a real possibility.

Hope you weren't expecting to burn less than that - that's isn't very much really doing central heating with wood. I think you'd find most in this thread over 5 and maybe more in the 7 range.

 

[brenndatomu]

Yup, 5 cords would be a minimum in MI. 5-7 would be reasonable. I burn about 5 myself (heating a average insulated 2000 ft house)

 

[j7art2]

I'm sure. I've got just over a full cord now, but have until Dec. 31 before my DNR firewood/fuelwood permit expires, so I need to get cracking. I think I'm going to invest in that thermostat though too, i was battling all morning with it. I have a feeling I'm going to just be supplementing with wood this year, but we'll see. Once hunting season is over, I'll have more free reign of where I can collect wood without issue, and it should be easier and quicker.