Please help with my Wood Furnace

[636Hooligan]

I bought this house 1 year ago. The furnace did alright, but wasn't near as hot as what you would expect.
This year has been fairly warm 0 to -2c and its been keeping the house pretty warm. Around 21-23c.
The temps started dropping this week (but its still not very cold) -5 to -9c at night, and up to 0 to -2c during the day.
The furnace is struggling now. I burned a bunch of wood yesterday and had the thermostat cranked (30c) and didnt break past 19.9c.

In the photo below you will see on the left side a bow in the firebox. But this was like this when I moved in. Last winter it was much colder (-30c and below), and albeit not as hot as it should be it did keep a comfortable 21-22c.

Its a valley comfort MP80 with an electric back up.
The ducting in the house could use improvement but, I dont think thats the main issue.
Door gasket was changed this season.
Chimney swept out
The buldge looks worse in photos than it really is
Filter is a bit dirty and will be changing today.
Vent on door is open just an 1/8th as per factory spec
Damper is controlled via thermostat and seems to be more ON/OFF than anything. In the shut position it is properly tuned to keep a fire alive.

In the future I play to switch to an outdoor boiler, but I need to get through this winter and possibly next aswell
Thank you in advance.
Greg

 

[Woodman2025]

Firewood quality? Moisture content?

 

[all night moe]

Firewood quality? Moisture content?

My 1st thought.

OP can you post a better pic of top of firebox? I will assume that it's just a warped baffle.

 

[636Hooligan]

Firewood quality? Moisture content?

Fire wood is mostly fir. 18% moisture or less.
Some birtch but I've only used a few pieces.
2x4 off cuts, split down for kindling
Birch paper for tinder

 

[636Hooligan]

My 1st thought.

OP can you post a better pic of top of firebox? I will assume that it's just a warped baffle.

 

[all night moe]

No concerns on safety. Just a baffle.

 

[636Hooligan]

No concerns on safety. Just a baffle.

Can you explain it to me?
Should the baffle be flat?
Or should it have some shape it?
If it should be flat, take it out and beat it flat?
What about the side that is bowed in?

Why would the baffle being o of shape cause the house to not get heated properly?

Lots of questions, but I appreciate your time

 

[Woodman2025]

If it's not wood quality, it's either lack of draft or lack of combustion air

 

[636Hooligan]

If it's not wood quality, it's either lack of draft or lack of combustion air

So the damper will be wide open when the thermostat is calling for heat. And the chimney pipe is clear... No dampers or anything like that

Any suggestions where to look ?

 

[Woodman2025]

I don't know if there is a channel the air flows through from the opening of the damper to the fire box? What is your chimney height and location?

 

[all night moe]

would the baffle being o of shape cause the house to not get heated properly?

No, this is not your issue.
It should be flat but won't be the source of your problem. I wouldn't recommend beating it flat just use as is.

You say you got the house last year. Last winter was somewhat mild. My guess is your house is not efficient. Heat loss and possible drafts.
When was it built?

 

[sloeffle]

Have you called Blaze King to get their opinion on what's going on ? The manual does call for specific draft setting, and without a baro and something to measure it with you are might be sucking all of your heat out of the flue.

 

[636Hooligan]

I don't know if there is a channel the air flows through from the opening of the damper to the fire box? What is your chimney height and location?

The air flows through the damper into 4 vents (you can see them in the photo I posted mid thread), when I remove ash today I will stick the leaf blower up the damper and see if that frees up some airflow. Although its not like the fire isnt burning hot.

Chimney is directly behind the unit on the exterior of the house. It is about 28' H.

 

[636Hooligan]

No, this is not your issue.
It should be flat but won't be the source of your problem. I wouldn't recommend beating it flat just use as is.

You say you got the house last year. Last winter was somewhat mild. My guess is your house is not efficient. Heat loss and possible drafts.
When was it built?

It was built in 95. I'm a carpenter and Ill say that its above average build quality for the 90s'. The attic insulation is quite good. And I have checked all the walls with an infared gun.
There are drafts from the windows, which I am slowly fixing. But that is the only major inefficiency.

While last winter was mild we did have a week or two at -30 to -35c and I really didnt notice any issues at the time

 

[636Hooligan]

Have you called Blaze King to get their opinion on what's going on ? The manual does call for specific draft setting, and without a baro and something to measure it with you are might be sucking all of your heat out of the flue.

I have not yet. but a Baro has been on my mind. It does seem to be keeping way less heat in the house than it should.... I know what a wood stove should do and this thing aint doing it.

What are the downsides of a baro? I've heard some poo pooing of them online

 

[sloeffle]

What are the downsides of a baro? I've heard some poo pooing of them online

The only downside is that it pulls warm air out of the house. I had one on my furnace and wouldn’t install a furnace without one. Kuuma actually ships their furnaces with baros. With your tall chimney, I would get a baro on it ASAP. I’d also get a Dwyer manometer too so you can measure what the draft truly is. I got mine off of eBay.

 

[all night moe]

Have you called Blaze King to get their opinion

Wow, I leaned something new today.
Had no clue BK made a furnace.

 

[brenndatomu]

Fire wood is mostly fir. 18% moisture or less

How exactly did you test it?
If you are just checking the outside, then it will be at least 10 points higher in the middle. Testing the ends or outside is meaningless.
You should resplit a room temp piece and immediately test it in the middle, preferably with meter pins parallel to the grain.

 

[brenndatomu]

Wow, I leaned something new today.
Had no clue BK made a furnace.

They don't anymore...haven't in quite some time

 

[brenndatomu]

I have not yet. but a Baro has been on my mind. It does seem to be keeping way less heat in the house than it should.... I know what a wood stove should do and this thing aint doing it.

What are the downsides of a baro? I've heard some poo pooing of them online

Well, I'd probably install a key damper and hook up a Dwyer Mark ll model 25 so you know where to set it.
A baro on a modern clean burn furnace exhausting into a properly sized and insulated chimney is fine, especially burning dry wood...there is a lot of misinformation out there about them.
However, with an old school "fire in a steel box" type furnace like this one, I'd probably tend to not install a baro, but definitely a manual key damper.
BK calls for -0.03" draft, which is really low, so with a 28' chimney, you very likely have much higher draft, and are blowing a ton of heat up the chimney.

 

[R Henderson]

I concur with the above I would definitely recommend getting a Dwyer or some other way to measure chimney draft. With my experience using it and a baro together by slowing my draft down I was able to keep more heat in the furnace/ plenum/ ducts. I'm not sure if the baro would affect the flue temps it doesn't matter much to my setup, but on an older, less cleaner burning unit it may or may not. It would not surprise me as tall as your chimney that it draws really hard and sucks more heat through the flue.

 

[R Henderson]

If you're furnace calls for 0.03 draft it would almost be worth it to check the draft even without a fire going. I've noticed mine will stay around 0.02 even with a cold furnace/ chimney and it is a shorter (18ft.) chimney however it is an insulated liner.

Curiously is your chimney on an exterior wall or located inside the house?

 

[sloeffle]

However, with an old school "fire in a steel box" type furnace like this one, I'd probably tend to not install a baro, but definitely a manual key damper.
BK calls for -0.03" draft, which is really low, so with a 28' chimney, you very likely have much higher draft, and are blowing a ton of heat up the chimney.

Does a baro just cause more creosote in your opinion with an "old school" furnace like this ?

 

[brenndatomu]

Does a baro just cause more creosote in your opinion with an "old school" furnace like this ?

It certainly doesn't help...especially if you have an oversized clay lined chimney, that'd be a creosote factory.
But a clean burning stove/furnace, and a properly sized insulated chimney, and burning dry wood, my experience is that it makes little difference, creosote wise

 

[all night moe]

I have 6' of nearly horizontal pipe before it hits the chimney of uninsulated lined 30' masonry chimney. On a cold start, it takes a couple mins to establish draft with a top down fire. Once going, all is well. Can hot reload, without opening bypass, and no smoke roll out.