Catalytic stove assistance

FishKiller · Jan 26, 2013

Hello All,
thanks for the help in identifying my stove model, it is indeed a Lopi flex. looks like an FX/SX? according to the manual. i have 35' on chimney, brick, and the stove is thimbled in on the main level (chimney goes to basement) about 25' from stove to top of chimney. everything was cleaned well before the season.
so this is my first cat stove and it came installed in the house. i have done some research before starting the season but i just want to talk to someone who runs one to make sure i'm doing everything right.
my current practices are as follows:
i always leave it in bi-pass mode until its hot and burning good, then engage the cat and start lowering the air as it stabilizes. typically burn at about 1/4 air or less.
flames appear strong but lazy with mostly secondaries.
i can look up through the door and see the cat is at least partially glowing while its burning, stops glowing when the flames die out.
there appears to be no smoke after the initial fire, however i can smell it outside and i notice it smells different then a normal wood stove burning, is this normal for cat stoves?
how do i know if the cat is running properly? it has a cat thermometer but it appears to not be working.
stovetop is really hot with cat engaged( i need to get an IR thermo to check it) and stove pipe is pretty warm, like lick your finger and get a sharp sizzle. (wouldn't dare try that on the stove top).
are there any important facts or tips or things i should know about running this stove?

just looking for someone to give me so tips.
thanks.

begreen · Jan 26, 2013

I would expect the cat to keep working for longer, but not having run this stove, or any cat stove for that matter I'm bumping this post for attention.

ddddddden · Jan 27, 2013

FishKiller said:
i have 35' on chimney, brick, and the stove is thimbled in on the main level (chimney goes to basement) about 25' from stove to top of chimney. . .

Does the thimble connect to a liner pipe inside the masonry, or just dump into it?
Is the masonry sealed off in/above the basement?

i always leave it in bi-pass mode until its hot and burning good, then engage the cat and start lowering the air as it stabilizes. typically burn at about 1/4 air or less. . .

Sounds about right.
How long are you leaving the bypass open?

flames appear strong but lazy with mostly secondaries.
i can look up through the door and see the cat is at least partially glowing while its burning, stops glowing when the flames die out. . .

How much time passes before it dies out? Temps would be helpful too.
Lazy secondaries = what I shoot for.
I have a different stove, but in mine, the whole cat glows at the beginning of the burn when there is plenty of smoke for the cat to feed on. The cat doesn't necessarily have to be glowing all the time, but when there's plenty of smoke, it gets hotter and will glow. After several hours, when the wood has all turned to coals, there is no smoke for the cat to burn.

there appears to be no smoke after the initial fire, however i can smell it outside and i notice it smells different then a normal wood stove burning, is this normal for cat stoves?

Yes, cat and non-cat secondary burn stoves burn the smoke, so it doesn't smell the same, but it's not completely odorless.

how do i know if the cat is running properly? it has a cat thermometer but it appears to not be working.
stovetop is really hot with cat engaged( i need to get an IR thermo to check it) and stove pipe is pretty warm, like lick your finger and get a sharp sizzle. (wouldn't dare try that on the stove top). . .

No smoke out of the chimney is a good indication that you have a good secondary burn, either in the firebox or in the cat. Yes, you definitely need some thermometers. I would try to replace the cat probe.

FishKiller · Jan 27, 2013

it does not have a liner that i am aware of, i've only cleaned from the bottom up and if there is a liner its not all the way to the basement. it isn't sealed between the basement and main level. i can and have run a brush all the way up. only access is the clean out in the basement, thimble, or from the top.

i leave the bi-pass open for 20-40 minutes if i'm starting from cold, maybe 10-20 if i have a good bed of coals and it takes off well.

the cat will glow for as long as there are strong flames, as it slows it stops. i watched it for an entire burn last night and was discouraged with what i saw. it only appeared to be glowing on one half of it, also seemed to be where all the gases were going through. it really seems like i have a restriction somewhere. i took the bricks out today and checked everything out, small amount of fly ash buildup but nothing crazy. the bipass seems to seal tightly when closed and after taking the cat out it was a clear path to the pipe. i attached

pictures, one of the cat in its holder, one of the holder without the cat and one of the behind the cat to the stove pipe with the bi-pass closed.... see anything wrong? besides the chip in the cat.

i also read there should be some gaskets that seal the cat? i have nothing, its just a rectangular box that fits into another metal box in the top of the fire box, its a tight fit... but not "sealed".

Backwoods Savage · Jan 27, 2013

Normally there is a gasket that the cat sits on.

You are probably not getting full use of the cat but it is at least partially working. Bear in mind thought that the cat does not have to be red. It will still work even though it does not appear to be working. Your cat shows some wear and tear as it is in the beginning stage of crumbling. Once this starts I don't think they last long at all. Be sure to handle with care when removing as it could crumble with a bump and they you clean up the mess. It appears that thing was run really hot at one point.

If you wish to try cleaning the cat with solution, let me know and I can send you directions.

FishKiller · Jan 27, 2013

yeah, i found out the hard way they are fragile when i first cleaned it. i'm going to hit a local stove store today and see if they can order me an new one as well as a new thermo, possibly a stovepipe probe as well.
i agree that it looks like it saw some heat, but that would have been before i started running it... nothing appears compromised, all seams and welds are good.
i probably won't burn again till i get at least a new thermo, take advantage of warmer weather this week and clean the chimney, maybe the stovepipe and stove as well. going in from the stovepipe will be the only way to really check for any hidden damage or air leaks that might be bi-passing the cat.
i should have done this at the beginning of the season, but i was told it was cleaned and it looked like it had been.

FishKiller · Jan 27, 2013

update.
just got back from the stove store, ordered a new cat (and a spare), replacement cat thermo and stove pipe probe. should all be in by the end of the week. luckily the weather is turning warm this week so i should be alright without a fire. sad to hear the heat kick on for the first time this year though.

i also used a mirror and flashlight to check the flue. no liner, terracotta bricks. and she is dirty. i know its from lots of cold starts (a lot of time running in by-pass mode), probably less then ideal wood, and general inexperience.
i'm learning a lot from reading the forums and have a plan of attack for tomorrow.

i'm going to start with the flue, top to bottom (i've been burning creosote logs and powder for the couple weeks to prep it for a cleaning). once its clean i will use a mirror and check the flue down to where the stove is thimbled in. i know to look for cracks and such, but anything else to look for?

next will be the stove pipe, take off and clean, get all the ash out and make sure the by-pass is sealing good and there are no separations at seams... anything else to look for while i'm in there?

shop vac everything out and put it all back together.

lesson learned, don't trust someones word that it was cleaned ::-)

thinking in the future... how would a liner work considering the flue is open all the way to the basement but the stove is on the main level?

ddddddden · Jan 27, 2013

FishKiller said:
it does not have a liner that i am aware of, i've only cleaned from the bottom up and if there is a liner its not all the way to the basement. it isn't sealed between the basement and main level. i can and have run a brush all the way up. only access is the clean out in the basement, thimble, or from the top.

Make sure that the cleanout door seals tightly. Air leaks there will mess with the draft in your stove. For best performance, you'll probably want to drop a liner down to the stove. What size is the chimney, 8 x 8" ?

i leave the bi-pass open for 20-40 minutes if i'm starting from cold, maybe 10-20 if i have a good bed of coals and it takes off well.

Sounds about right.

the cat will glow for as long as there are strong flames, as it slows it stops.

I'm thinking that your chimney might be too large for the stove, so when you don't have a hot fire, you don't have enough draft.

i watched it for an entire burn last night and was discouraged with what i saw. it only appeared to be glowing on one half of it, also seemed to be where all the gases were going through. it really seems like i have a restriction somewhere. i took the bricks out today and checked everything out, small amount of fly ash buildup but nothing crazy. the bipass seems to seal tightly when closed and after taking the cat out it was a clear path to the pipe. . .

i also read there should be some gaskets that seal the cat? i have nothing, its just a rectangular box that fits into another metal box in the top of the fire box, its a tight fit... but not "sealed".

Yeah, there's always a good chance that a used cat is nearly worn out. In your 2nd pic, I can see gasket material around the cat, but the fit doesn't look snug.

http://www.woodstovecombustors.com/Gasket_Details.html

http://www.woodstovecombustors.com/lopi.html

ddddddden · Jan 27, 2013

FishKiller said:
thinking in the future... how would a liner work considering the flue is open all the way to the basement but the stove is on the main level?

Liner drops down and connects to the thimble. Think of it as a stove pipe.

What is the diameter of the flue on your stove?

What is the size of your masonry chimney?

FishKiller · Jan 27, 2013

ok, that's kinda how i thought it would work,

chimney flue is 8"x8", and about 25' from thimble to top (add 10' or so to basement) and its 8" diameter 24 gauge on the stove pipe.

as a side note, the chimney system is actually 3 flues, 1 for the boiler, 1 for the stove and 1 not in use (6x6, runs to the basement with a thimble set up for a secondary stove in the basement).

ddddddden · Jan 27, 2013

8 x 8" (64" sq) isn't too big for a stove with an 8" flue collar (~50" sq), but it's possible that your chimney is leaking through the cleanout or somewhere else. Any air that gets pulled in elsewhere = air that doesn't get pulled through the stove. Even if there are no leaks, I wonder how that 10' going down to the basement could affect draft. . .seems like a reservoir of air that could be mixing with the stove exhaust and cooling it, reducing draft. Cats need very good draft to keep 'em purring.

I'd want to use a liner, but an 8" pipe isn't going to fit down an 8 x 8" chimney. You could bust out the 8 x 8" clay flue tiles to make room, or you could put in a 6" pipe. . .and a different stove, which you might want to do in a few years anyhow, especially if you hang around here. ==c

FishKiller · Jan 28, 2013

thanks,
the cleanout door is just cast iron, it shuts tight but there are no gaskets or locks on it. come to think of it, when i open the cleanout door i get a ton of draft with the stove not even running, seems like more then i get from the stove when its running. could this be the extra 10'? or just the fact that its a straight shot rather then the two 90's the stove pipe makes (just one in the pipe, and one at the thimble). considering there is that 10' of cold air, i might try to seal the cleanout door better. any suggestions?

i think most of my current problems are draft (i see what you mean about the cat needing a ton), i think a good cleaning might solve the problem, which i was ready and motivated to do today... and i woke up to snow and ice falling from the sky (won't be up on the roof till it changes to rain). I'll update when i get her up and running again. i just need to get through this year. who knows... if i can figure this stove out and get it running good i might stick with it, sure does throw some heat. but what I've learned is cat stove + newbie = problems

ddddddden · Jan 28, 2013

FishKiller said:
thanks,
the cleanout door is just cast iron, it shuts tight but there are no gaskets or locks on it. come to think of it, when i open the cleanout door i get a ton of draft with the stove not even running, seems like more then i get from the stove when its running. could this be the extra 10'? or just the fact that its a straight shot rather then the two 90's the stove pipe makes (just one in the pipe, and one at the thimble).

Both.

Height increases draft, and elbows reduce it.

considering there is that 10' of cold air, i might try to seal the cleanout door better. any suggestions?

https://www.hearth.com/talk/threads/sealing-off-exterior-chimney-cleanout-is-it-a-good-idea.59582/

i think most of my current problems are draft (i see what you mean about the cat needing a ton), i think a good cleaning might solve the problem, which i was ready and motivated to do today... and i woke up to snow and ice falling from the sky (won't be up on the roof till it changes to rain). I'll update when i get her up and running again. i just need to get through this year. who knows... if i can figure this stove out and get it running good i might stick with it, sure does throw some heat.

Lopi makes good stoves. Might be a keeper.

If you decide you want something else, you will have a better idea of what you want after burning this one for a season or two.

I was thinking about new stoves because of the liner. It would suck to go through the trouble to put in an 8" liner for this stove, and then decide that you want a new stove; most new stoves use 6".

Is this your Lopi?
https://www.hearth.com/talk/threads/an-older-lopi-i-need-help-iding.57494/

. . .but what I've learned is cat stove + newbie = problems

All secondary-burn stoves need dry wood and are a bit more complicated to operate than older stoves that don't try to burn clean. Cats aren't that bad. . .1 extra step: close the bypass to engage the cat. Establishing a good secondary burn with a non-cat requires adjusting the draft just as much as or more than a cat does, just no bypass to close. IMO, the bypass is helpful for cold starts in draft-challenged installations, because it bypasses the restrictive secondary-burn plumbing. Some non-cats, with some Lopis among them, have secondary bypasses.

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Catalytic stove assistance

FishKiller

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begreen

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ddddddden

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Backwoods Savage

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