catalytic stove questions

[fabguy01]

was just curious on how catalytic combustor stoves respond to different wood? like pine, punky wood, wet wood, and wood that has not been properley seasond

 

[Todd]

Don't burn wet wood in a cat stove, it will clog up the cat and could cause thermal shock cracking or crumbling. As long as the wood is dry, any type burns fine. You just don't get the long burns with the lighter woods.

 

[fabguy01]

Thanks, Ive been thinking of replacing the double 55 drum stove in the shop and thought i could get a deal on somthin this time of year.

 

[Pine Knot]

I routinely mix some "less than fully seasoned oak" with drywood, and if I add more than a couple of sticks the cat temp seems to not rise as high as with all dry wood. But adding some higher moisture wood will extend burn time somewhat. Really wet wood is a disaster in cat stoves. I haven't used pine except for kindling.

 

[Wet1]

Interestingly enough, I was talking to a BK dealer in ME the other day (hell of a nice guy BTW) and he was saying he only burns green wood in his stoves, which are all cat stoves. He said he has been burning only green wood for well over 20 years in his BK stoves and has never had a problem. He probably hasn't had any problems (that he knows of anyway), but my guess is he hasn't had any problems because he turns his stoves every year (sells them as demos) before complete cat failure would have had a chance to occur.

What happens with a traditional ceramic cat is the catalyst can crack over time when the cold cat is 'shocked' with the hot steam from engaging the cat while burning green wood. Over a period of time these cracks build up and the cat will fail (fall apart) when it is repeatedly shocked with this steam. The cat manufacturers are very clear that burning green wood will drastically reduce the life of a traditional ceramic cat.

On a somewhat related note... I understand BK is now starting to beta test SS cats with their stoves. Their new stoves (King models only) being made right now are shipping with SS cats. I don't know much about SS cats, but I understand they are not nearly as prone to cracking due to thermal shock, so they could prove to be more reliable and resilient to this phenomenon. I hear the the SS cats light off a little sooner as well, but I haven't seen any data first hand to prove this is true. It will be interesting to see how these SS cats pan out over the long run.

 

[mellow]

I know with mine, as soon as I had to use my not as seasoned wood I saw the cat would not lite as long as usual, the moisture is cooling the cats off a lot quicker than normal. My cats are in needing of replacement anyway so I am not to worried about the thermal shock issues, but if you had a newer cat that would be one reason to not burn green wood.

 

[Todd]

Well, I have had problems with cracking cats even though my firewood has been under 20% moisture. They still work as long as they are held together in a metal can or frame and could stay intact for years this way before crumbling. I'm still trying to figure out what my problem is along with Woodstock. They keep sending me new ones for free and I asked them about the steel cats, the person stated they looked at them a few years back but couldn't remember why they decided to stick with the ceramic ones. I think it would be a no brainer to go with steel since they are more durable.

 

[raybonz]

was just curious on how catalytic combustor stoves respond to different wood? like pine, punky wood, wet wood, and wood that has not been properley seasond

I burn almost all oak and it runs great as long as it is not wet... Cat stoves hate wet wood! I have heard that pine tends to shorten combustor life and I never burn it.. As for the combustor cracking my stove has a cast grate that sits under the cat to prevent or reduce direct flame contact with the cat as that would tend to crack it.. Or as they refer to to it as "flame impingement".. My cats last about 10 yrs.... They must have done something right or maybe I am doing something right? I did replace my cat grate last year as it had developed a crack but it was intact.. First part I have ever bought for this stove in over 20 yrs...

Ray

 

[myzamboni]

Interestingly enough, I was talking to a BK dealer in ME the other day (hell of a nice guy BTW) and he was saying he only burns green wood in his stoves, which are all cat stoves. He said he has been burning only green wood for well over 20 years in his BK stoves and has never had a problem. He probably hasn't had any problems (that he knows of anyway), but my guess is he hasn't had any problems because he turns his stoves every year (sells them as demos) before complete cat failure would have had a chance to occur.

What happens with a traditional ceramic cat is the catalyst can crack over time when the cold cat is 'shocked' with the hot steam from engaging the cat while burning green wood. Over a period of time these cracks build up and the cat will fail (fall apart) when it is repeatedly shocked with this steam. The cat manufacturers are very clear that burning green wood will drastically reduce the life of a traditional ceramic cat.

On a somewhat related note... I understand BK is now starting to beta test SS cats with their stoves. Their new stoves (King models only) being made right now are shipping with SS cats. I don't know much about SS cats, but I understand they are not nearly as prone to cracking due to thermal shock, so they could prove to be more reliable and resilient to this phenomenon. I hear the the SS cats light off a little sooner as well, but I haven't seen any data first hand to prove this is true. It will be interesting to see how these SS cats pan out over the long run.

Please list the name of the dealer so we all know not to by demo models from him.

 

[gyrfalcon]

Well, I have had problems with cracking cats even though my firewood has been under 20% moisture. They still work as long as they are held together in a metal can or frame and could stay intact for years this way before crumbling. I'm still trying to figure out what my problem is along with Woodstock. They keep sending me new ones for free and I asked them about the steel cats, the person stated they looked at them a few years back but couldn't remember why they decided to stick with the ceramic ones. I think it would be a no brainer to go with steel since they are more durable.

For us non-cat owners considering getting a cat, and particularly a Fireview, could you explain what you mean by "as long as they are held together in a metal can"? I literally have no idea whatsoever what to make of that!

My only hesitation about getting a Woodstock is exactly this kind of thing, that I feel like I'm on Mars when I read you guys talking about things like this.

It's reassuring as heck that Woodstock is continuing to send you new ones while you all try to figure out what the problem is long distance, but not having any kind of warm body available to come look at the darn thing and figure out why it might be having a problem is what's really intimidating to me. Whatever "held together in a metal can" means, it's not likely to be something I could do myself.

 

[Peter B.]

Most cats have a light, rigid stainless steel surround or frame around them. I think the main reason is to help preserve physical integrity of the ceramic.

My last (older make) cat was a Corning... and lasted 3-5 years as I recall, but the coating was peeling from the ceramic sub strata (grid/honeycomb) so I replaced it. Results aren't in yet on my current cat (also an old 'hand me down' Corning).

First month of burning and all is well.

Peter B.

-----

 

[Todd]

Well, I have had problems with cracking cats even though my firewood has been under 20% moisture. They still work as long as they are held together in a metal can or frame and could stay intact for years this way before crumbling. I'm still trying to figure out what my problem is along with Woodstock. They keep sending me new ones for free and I asked them about the steel cats, the person stated they looked at them a few years back but couldn't remember why they decided to stick with the ceramic ones. I think it would be a no brainer to go with steel since they are more durable.

For us non-cat owners considering getting a cat, and particularly a Fireview, could you explain what you mean by "as long as they are held together in a metal can"? I literally have no idea whatsoever what to make of that!

My only hesitation about getting a Woodstock is exactly this kind of thing, that I feel like I'm on Mars when I read you guys talking about things like this.

It's reassuring as heck that Woodstock is continuing to send you new ones while you all try to figure out what the problem is long distance, but not having any kind of warm body available to come look at the darn thing and figure out why it might be having a problem is what's really intimidating to me. Whatever "held together in a metal can" means, it's not likely to be something I could do myself.

In the Fireview the ceramic catalyst is contained inside a cast iron 2 piece jacket (metal can) and this jacket sits on an opening to the firebox. If you go to the Woodstock site and click on the cat cleaning slide show it shows this. Woodstock will bend over backwards for you. I didn't even ask them to send me the last cat. They asked me if I wanted a new cat and I told them I'd continue to burn it til it didn't work anymore and a few days later, surprise, the UPS man delivered one. I've narrowed my problem down to overdrafting and use a pipe damper to slow it down, but I may remove my 5.5" liner and just go with the original 6x10 clay tile flue.

 

[gyrfalcon]

Most cats have a light, rigid stainless steel surround or frame around them. I think the main reason is to help preserve physical integrity of the ceramic.

My last (older make) cat was a Corning... and lasted 3-5 years as I recall, but the coating was peeling from the ceramic sub strata (grid/honeycomb) so I replaced it. Results aren't in yet on my current cat (also an old 'hand me down' Corning).

First month of burning and all is well.

Peter B.

-----

Thank you. In other words, the "metal can" isn't something he constructed, it's already something that's part of the stove or comes with the cat itself. I get it. I do tend to get paranoid about this stuff because I just don't have the tools, expertise or experience to improvise the kinds of things so many of the incredibly smart and handy people here seem to do routinely.

So if the cats works fine even if it's in pieces inside the frame, why does Woodstock keep sending him new ones?

 

[gyrfalcon]

In the Fireview the ceramic catalyst is contained inside a cast iron 2 piece jacket (metal can) and this jacket sits on an opening to the firebox. If you go to the Woodstock site and click on the cat cleaning slide show it shows this. Woodstock will bend over backwards for you. I didn't even ask them to send me the last cat. They asked me if I wanted a new cat and I told them I'd continue to burn it til it didn't work anymore and a few days later, surprise, the UPS man delivered one. I've narrowed my problem down to overdrafting and use a pipe damper to slow it down, but I may remove my 5.5" liner and just go with the original 6x10 clay tile flue.

Gotcha. I'm calm now.

I know Woodstock has an unparalled reputation for support, but that isn't always a complete substitute for a warm and knowledgeable body on the spot, so I'm still biting my fingernails a bit on this whole idea.

 

[Todd]

In the Fireview the ceramic catalyst is contained inside a cast iron 2 piece jacket (metal can) and this jacket sits on an opening to the firebox. If you go to the Woodstock site and click on the cat cleaning slide show it shows this. Woodstock will bend over backwards for you. I didn't even ask them to send me the last cat. They asked me if I wanted a new cat and I told them I'd continue to burn it til it didn't work anymore and a few days later, surprise, the UPS man delivered one. I've narrowed my problem down to overdrafting and use a pipe damper to slow it down, but I may remove my 5.5" liner and just go with the original 6x10 clay tile flue.

Gotcha. I'm calm now.

I know Woodstock has an unparalled reputation for support, but that isn't always a complete substitute for a warm and knowledgeable body on the spot, so I'm still biting my fingernails a bit on this whole idea.

Aren't you right in their neighborhood? Go take the tour. You sound just like I did 4 years ago, I was afraid of the bad rep for cat stoves, but bit the bullet thinking if it didn't work out I had 6 months to return for a full refund. No other stove company has that guarantee.

 

[gyrfalcon]

Aren't you right in their neighborhood? Go take the tour. You sound just like I did 4 years ago, I was afraid of the bad rep for cat stoves, but bit the bullet thinking if it didn't work out I had 6 months to return for a full refund. No other stove company has that guarantee.

Well, I'm "in the neighborhood" compared to, say, Oregon. But yes, I do plan to take a trip over there when the weather warms up and I don't have to worry about freezing to death if my ancient Jeep breaks down. I'm not particularly worried about the first six months but several years down the road. When the price of oil goes up again, which it will, I literally will be unable to afford to live here without a functioning woodstove, so it's a pretty criitical matter for me.

One would think a very tenderly treated (secondhand) 4-yo stove from a top-line manufacturer, which is what I have now, would be utterly trouble free, but I've had a world of trouble with the door latch since having the door gasket replaced this fall by my sweep/installer precisely per the dealer/manufacturer's instructions. After struggling with it myself all winter, I'm about to remove the whole frame and door assembly and haul it up to the dealer some 50 miles from here to see what they think. And worst comes to worst, I at least have the option of paying them to send somebody down to figure out what the problem is and fix it for me.

 

[rickw]

If you are considering a Woodstock but are scared of the cat, just read all the stove rating comments for Woodstock (these are available at the home page of hearth.com, you have to look around a little bit). Basically everyone is happy with the stove. If there was a chronic problem with cat longevity it would show up in user reviews.
I haven't had mine long enough to worry about replacing the cat yet, but at $125 each it doesn't strike me as too horrible to replace it every 3-4 years. It is certainly easy enough to get at. The main benefit is economy and reduced stove loadings. I'm burning maybe 60% of the wood that I used with my old Lopi, and only load it 2-3 times a day.

 

[Backwoods Savage]

In the Fireview the ceramic catalyst is contained inside a cast iron 2 piece jacket (metal can) and this jacket sits on an opening to the firebox. If you go to the Woodstock site and click on the cat cleaning slide show it shows this. Woodstock will bend over backwards for you. I didn't even ask them to send me the last cat. They asked me if I wanted a new cat and I told them I'd continue to burn it til it didn't work anymore and a few days later, surprise, the UPS man delivered one. I've narrowed my problem down to overdrafting and use a pipe damper to slow it down, but I may remove my 5.5" liner and just go with the original 6x10 clay tile flue.

Gotcha. I'm calm now.

I know Woodstock has an unparalled reputation for support, but that isn't always a complete substitute for a warm and knowledgeable body on the spot, so I'm still biting my fingernails a bit on this whole idea.

gyrfalcon, I agree that Woodstock has an unparalled reputation. They are just good plain folks there.

Back to the cat. Cleaning or replacing the cat is very simple and quick. My wife can and does do this all by herself if needed. All that needs done is to lift the top lid (it has a nice handle and is on hinges), which is heavy but not so heavy that a lady can't lift it.

The first time you clean the cat you have to remove two bolts. A simple socket wrench or even a crescent wrench works fine. Once those bolts are removed you do not have to reinstall them if you don't want to as they are there for shipping purposes.

You simply then lift the cat out (you might need both hands as it doesn't fit small hands really well). I take it outdoors immediately and use an old paint brush to brush away the fly ash, which is very fine white ash. Looks more like dust or flour. Then it is simply a matter of sitting the cat back in the stove, closing the lid and relighting the fire.

We do this a couple of times per winter. If we happen to get a warm afternoon and we haven't added any wood to the fire, then I'll do a quick clean. So far this year I've done that 2 or 3 times (don't remember for sure). My memory is failing me. Senior moment?!

Then in the spring after the heating season is over, do another clean along with all the stove cleaning details and you are good for another season.

Wish we were closer so we could help you and you could come and watch us clean the stove. However, pictures and this forum will have to do along with talking to the good folks at Woodstock.