20 year old Cat

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sparklow

Member
Sep 4, 2008
66
North-central CT
I've been debating with myself whether or not to post this but here goes. I have a twenty year old CDW Federal Airtight A Plus catalytic stove ( and yes I burn it every year) and I'm still using the original Cat. Some of you aren't going to believe me but it's true. I can still get the Cat thermometer to 1200 degrees easily. I haven't the slightest idea why it has lasted this long and I bought a replacement Cat a year ago (not installed yet) just in case. So, anyone else had one last like this or is this totally rare?
 
20 years is a long time for a cat, you must be doing something right. See any smoke out the chimney?
 
The only thing I'm probably doing right is that I've got a lot of experience with the stove. When it's up to temp. with the Cat engaged there is little to no smoke from the chimney. When it is really cold out, like now, I run it with the Cat in and as hot as I can get it, 1100-1200 degrees, as the stove is a bit undersized for my house. The cast iron of the stove is in really great shape for twenty years old and obviously the Cat doesn't mind this kind of treatment, maybe thats why it has lasted for so long.
 
sparklow, most of us will be happy to get half that. Congratulations!
 
I've currently got a cat in use that's 'historically' that old but didn't see service for some 15 years or so. A friend with a Dutchwest gave it to me when he pulled it from his stove and burned without. (I couldn't talk him out of doing so.)

It's a Corning cat, and I first installed it in my stove last year, replacing a no name brand I'd used happily for multiple years.

With the set up on my stove, the cat slides forward or back to engage or disengage. I have a probe that sits right over the spot where the cat sits... or doesn't sit... depending on position. All exhaust from the stove passes through the same chamber and past the probe tip, whether the cat is engaged or not.

With either the old cat or the Corning, I've found that if I'm burning hot, the probe will reflect (internal) stovetop temps in catalyst range - 1000 to 1500 - whether the cat is actually engaged or not.

In other words, in that region of the stove, when burning hot, those temps are possible with or without the cat.

I think the cat still cleaned up the exhaust somewhat, but it was of interest to me that comparable temps were achievable without.

Sadly, before putting the Corning into use this year, I immersed it in medium hot water to clean it... and (I think) the result was that most of the catalyst flaked off. There was quite a lot of debris - dark grey in color and not resembling fly ash. I was surprised and chagrined, but I put it back in the stove... and now use it as a damper or flow reducer to help control the stove's output.

The stove (and my 20 year old modifications to it) are showing their age, and I won't likely use the stove again after this year... but haven't settled on an alternative yet.

Just a sidebar of sorts, I guess.

Peter B.

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All I have ever done to maintain the Cat is vacuum it every Fall before burning season. I think that the less I move it around the better, it's only been removed from the stove maybe twice in twenty years. On my CDW A Plus the smokepath is either up the pipe or through the Cat. I don't read high temps. (700+) unless the Cat is engaged. By the way, as an aside, I have been mixing seasoned cord wood with BioBricks for the last several years and I am very happy with the results, this works very well in a Cat stove.
 
Peter B. said:
With either the old cat or the Corning, I've found that if I'm burning hot, the probe will reflect (internal) stovetop temps in catalyst range - 1000 to 1500 - whether the cat is actually engaged or not.

In other words, in that region of the stove, when burning hot, those temps are possible with or without the cat.

I think the cat still cleaned up the exhaust somewhat, but it was of interest to me that comparable temps were achievable without.

Sadly, before putting the Corning into use this year, I immersed it in medium hot water to clean it... and (I think) the result was that most of the catalyst flaked off. There was quite a lot of debris - dark grey in color and not resembling fly ash. I was surprised and chagrined, but I put it back in the stove... and now use it as a damper or flow reducer to help control the stove's output.
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Interesting results. Do you find that the temperature on the probe will drop if you have high cat temps and a smoldering/low fire and the cat is moved into the bypass position? If so, then you can be sure that your cat is at least somewhat effective. Of course, if the probe temp doesn't climb fairly quickly after engagement above 5-600F, then the cat is likely shot.

I'd be surprised if the catalyst was removed via a hot water bath - that is the prescribed method of cleaning (plus a little vinegar) of a lot of brands. The big no-no is high pressure air or mechanical scrubbing inside of the cat cells.
 
Todd said:
Have any pictures of that old stove?

Todd:

I'm guessing this question was directed at me. Below is a pic of what my stove would look like if restored.

Mine isn't anywhere near so 'shiny'.

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pgmr said:
Interesting results. Do you find that the temperature on the probe will drop if you have high cat temps and a smoldering/low fire and the cat is moved into the bypass position? If so, then you can be sure that your cat is at least somewhat effective. Of course, if the probe temp doesn't climb fairly quickly after engagement above 5-600F, then the cat is likely shot.

I'd be surprised if the catalyst was removed via a hot water bath - that is the prescribed method of cleaning (plus a little vinegar) of a lot of brands. The big no-no is high pressure air or mechanical scrubbing inside of the cat cells.

pgmr:

I don't guess I've ever tried your first suggestion, though it should have been an obvious way to test my observation... I will give it a try soon.

With a brand new cat, I can recall seeing a noticeable surge in temp when the cat was engaged. With an older unit, there does not seem to be a lot of difference.

I don't fully trust the probe I'm using now for accuracy and it's rather slow to respond... but yes, I've definitely seen temps _well_ over 1,000* (adjusted for believed error in the probe) at the top of the stove with the cat disengaged. Again, this is through a hole I drilled into the stove 'crown'... originally in order to monitor cat temps.

I have no way of knowing whether the debris that rinsed off the cat was the 'good stuff' or not... and yeah, I was only following what I thought was a safe method for cleaning (if not strictly by the book).

We've got plenty more 'weather' yet here this winter in Wisconsin, and I still like to play with the stove, so maybe I'll do some more tests in days to come.

Peter B.

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