Need your help?

[AppalachianStan]

I have and old 1978 Appalachian 58 wood stove with a class A SS 8" chimney that is from the top of stove to the chimney cap is 15'. 5' of that is black stove pipe. I just put the cats in the stove in Feb of this year. the wood is so so but it was CSS in Nov of last year. The stove will hold its temps from 5 hours be for its starts to drip. I have been getting temp 375* on stove top, 200* Stove pipe and 1000 to 800* on the cat probe on the last 6 burns. My stove back puffs if I close the bypass damper. But if I live it open just a little it stops. I just had the stove top up to 500*, stove pipe to 300* and the cat up 1100* by living the damp open a little, but if I close it then the fire go out and it starts back puffing. I do not want to over the stove. Would a 6" stove pipe inside help with this? Any help would be great?

 

[webbie]

Being a double wall stoves, you can't use surface temperatures in the same way as you would with a single wall one....

A 6" pipe would not help the situation. You should be able to completely close the bypass and have all the smoke go through the cat converter - that is, after you close the bypass, you should be able to control the air using the air inlets (does that have little slides on the door or below for incoming air?)

It may be that you are getting too much of a fire going before you close that bypass - too much wood all heated up at once, and then when you close it there is too much smoke. You may be able to control this by raking the coals properly before loading or reloading (rake them toward the air inlet somewhat) and then closing the damper sooner. You might find that raking the coals all the way to the left or right of the firebox before reloading does the same thing - that is, makes sure the wood is not all generating smoke at once. Think of it as metering the burn.

 

[AppalachianStan]

I rack all the coals to the front by the door this is where most of the air come in to the box. The air comes in at the top of the glass and at the bottom of the fire box.

 

[AppalachianStan]

Have seen on here posts that say load it with wood to the top of the fire bricks but my bricks are about 4" tall. Are these cat stove all ways have a low stove pipe temp? I can not get the pipe pass 200 unless I open the bypass a little.

 

[webbie]

That's a big pipe size, so it will likely run a lower stat temperature. You would get more accurate results using a probe thermometer which went to the center of the pipe.

Ideally, a good cat stove would run a lower stack temps because most of the gases are burnt in the catalytic converter. If the temperature in or above the converter is over 500-600 degrees, then it is working.

The chimney seems plenty tall - especially if it is straight up. It may actually have an overdraft (too strong) at certain points in the fire and that may cause the back puffs. There are different kids of back puffs, but some of them are because of delayed ignition of the gases inside the stove - that is, they build up and then ignite, etc.

Sometimes a stack damper or a barometric damper on the stove pipe can fix that problem.

 

[AppalachianStan]

It started back puffing Pipe is at 250* and the cat probe is at 1200* bypass close air slider was close is got 2 to 3 splits to burn. Now the cat probe is dropping. still back puffing. ?

 

[AppalachianStan]

Cat probe is just under 1200*. looks like it going back up.

 

[AppalachianStan]

but some of them are because of delayed ignition of the gases inside the stove - that is, they build up and then ignite, etc.

That is the type of back puffing I am getting. It looks like the cat probe is holding at 1200*

 

[AppalachianStan]

If the temperature in or above the converter is over 500-600 degrees, then it is working.

The probe is about a 1/4" in front of the cats. Not in the converter.

 

[AppalachianStan]

It all ways does this at the end of a load just as it picks and the the temps will drop. This is the hot I have got the stove. I have not loaded it all the way up. this was on 5 small splits.

 

[webbie]

I do think it's a matter of balance between the stove and the chimney. Chances are that these older cats were not highly engineered - that is, not like today's stoves.

Your cat is running quite hot for a typical burn - as I said, it's fine for it to drop down to 700+ degrees, it's still working fine at those temps. When it is running too hot, that means too much smoke for it to burn which sets up that backpuffing.

If it were mine, I'd probably install a barometric draft regulator on the pipe, which may help balance it out. What is probably happening is that so much fuel (smoke) is being generated that the cat can't combust it all, so the stove and part of the pipe is filling with a rich (unburnt) mixture and then it being lit off by the high temps of the cat.

 

[AppalachianStan]

My dad had a barometric draft regulator on his old stove for years. But I took out the old chimney and put in the class A chimney. Can it be it is getting to much air. The cats are new but small 2" x 2" x 7" each. The door glass is missing the gasket from the top it looked like a air wash but it may need the gasket same on the side glass. I also rack coals to the right side put in 2 small split this morning got them cherryed for about 5 min ans closed the door and now the cat probe is up to 800*

 

[webbie]

I would definitely add the gasket on the side glass. If you put it on the front glass, it may get much dirtier, but if that does not matter it may help. Those areas may be letting in the air which causes the puffing.

But, all in all, a baro or a turn damper may serve better to balance the whole system.

 

[AppalachianStan]

I will put the gasket in tonight when I get home from work. and if that don't work. If that don't work I get a turn damper for the stove pipe. Thanks webbie.

 

[mellow]

I don't think you have a good draft as I have mentioned in your last post about this. You need to look at your chimney setup, maybe try replacing that single wall with double wall or try sticking single wall on your outside stack temporarily to see if that improves your draft, then you will know you need more chimney.

 

[AppalachianStan]

It may actually have an overdraft (too strong)

Ok one say it may be too strong

I don't think you have a good draft

and one say not a good draft.
I just don't have the money for double wall stove pipe or class A chimney right now. I can try the gasket I have some left over when I did the gaskets in the stove. I can get 36" black stove pipe from Lowe's to see if that works.

 

[AppalachianStan]

So far so good the gasket at the top of the door seems to be working and the glass is still clean, but will see on next load.

 

[oldspark]

Dont think you will get an over draft from 15 feet of pipe.

 

[AppalachianStan]

I guess I will try to add some pipe to the top of my chimney Saturday. So far no back puffing but it is not getting enough air with the air side all the way open. The bypass is closed. So it looks like the gasket at the top of the door glass made it worse. This load has been going over a hour the cat probe is at 700* stove pipe is at 175* and there is small flames in the box. but the glass is still clean.

 

[AppalachianStan]

Take that back it started back puffing at 700* on the cat probe. I need to stay warm the winter. I do not like this stove at all.