Shelter SF2626 - Novice

[Toasty Shelter]

Hello everyone, new to Hearth and to the wood furnace world. I had the existing Shelter furnace cleaned before I started this years' burns. First 3 went well, atleast to my understanding, temps held about 400f. By morning I had little to no coals left, assuming i did not load it enough. We are using cherry, oak, hickory, and birch mainly. Seasoned and cut from our land. Our 4th burn had bad downdraft issues and could not hold temp or give enough updraft for the smoke to escape. Since then we had extended the chimney and put a new stainless cap on. The professional service we had out mentioned our chimney being undersized. It has a 7" clay liner...would this aid in the restriction of updraft?
My main question is what are the best methods to heat the chimney to ensure an updraft is created? Propane torch, hairdryer, newspaper are a few ideas i have found. I have also read about a fan that can be installed up at the cap to pull the air up. Is that worth looking into? I would assume it becomes another item to clean...
Again, brand new to this and trying to find as much time as I can to learn this art. Any feedback/tips & tricks are greatly appreciated as I understand each setup and scenario is different from the next.

 

[brenndatomu]

I have also read about a fan that can be installed up at the cap to pull the air up. Is that worth looking into? I would assume it becomes another item to clean...

Yeah, skip that.

Our 4th burn had bad downdraft issues and could not hold temp or give enough updraft for the smoke to escape.

You are saying you had no draft when lighting the fire? What was the weather like outside...temp?

Since then we had extended the chimney and put a new stainless cap on. The professional service we had out mentioned our chimney being undersized. It has a 7" clay liner...would this aid in the restriction of updraft?

7" is not undersized for that unit...manual calls for 6" round, no?

We are using cherry, oak, hickory, and birch mainly. Seasoned and cut from our land.

What does "seasoned" mean? How long was it cut, split, stacked, and drying before burning it?

As far as how to preheat the chimney...I like a propane torch or a hair dryer.

Did you have any fans running in the house when this draft event happened? Bath or kitchen fan, dryer, central vac system? That will screw with draft at startup sometimes, especially if it wasnt real cold outside.
You might try cracking a nearby window the next time this happens...see if you have a negative pressure situation going on...

 

[Toasty Shelter]

Yeah, skip that. - ✔️

You are saying you had no draft when lighting the fire? What was the weather like outside...temp? - Lit fairly well, but immediately kicked smoke back down and out the door. The Shelter unit is located in our garage which is partially underground with living space above it. I opened the garage door, but the unit still smoked and started pushing out the flue pipes. Weather was about 30F, snowy, & windy. We are low and cut back around trees so the wind likes to swirl a bit.

7" is not undersized for that unit...manual calls for 6" round, no? - From what I read, it is accurate for the unit. I wonder if the clay to the stainless insert would make much difference?

What does "seasoned" mean? How long was it cut, split, stacked, and drying before burning it? - Wood has been sitting for at least a year. Outside typically stacked under tarps. The previous owner has quite a few stacks all over the property. Wood I just brought in reads 11-14 moisture and split the highest I have seen is 17%.

As far as how to preheat the chimney...I like a propane torch or a hair dryer. - Ran a hair dryer today, then the torch for awhile. Have had a warm house for about 9 hrs now. Curious....my Honeywell Fan Limit Switch seems to run the blowers even after temps have been met. Is this normal? The blower connected to the limit switch is acting as a cooler for the furnace box itself? If so, my issue becomes the flue starting to lose temp 250-300F while the house is becoming too warm.

Did you have any fans running in the house when this draft event happened? Bath or kitchen fan, dryer, central vac system? That will screw with draft at startup sometimes, especially if it wasnt real cold outside.
You might try cracking a nearby window the next time this happens...see if you have a negative pressure situation going on... - No fans running, my assumption is it could not get hot quick enough...taking it all as a learning curve.

Appreciate the assistance!

 

[brenndatomu]

A stainless liner sure wouldn't hurt...especially if it was insulated...which is highly recommended...but not sure you'll have the room for it in a 7" flue...it would be tight just a bare liner, I'm saying you'd have to break the tiles out to fit an insulated liner (it would make for superior chimney/draft though)

That's 11-14% moisture checked in the middle of a freshly split piece? Checking end grain or the "outside" of a piece of wood means almost nothing.

Yes, your fan/limit switch is monitoring the supply plenum temp only, no tstat input to it...you can adjust the temps that it operates at though...just look up a manual for that model FLS to see how to set it...its pretty easy really. 140-150* on and 110-120* off would be pretty typical on an old school wood furnace.