What's the max temp in the refractory unit, for a Defiant Encore

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SonOfEru

Member
Jan 11, 2018
133
Sanbornton NH
I bet this has been asked before, but I didn't find an answer. I have a Defiant Encore 0028, from back around 1990. I got it used. I have an Auber AT100, and I always kept an eye on it, but didnt have much cause for concern. This year I decided to replace the catalytic, using a Condar after-market, and the change is dramatic. When I took out the old one it was badly cracked and the frame was warped.

Now I find it goes up to 1300 or so quite easily, and I have to spend more time watching and controlling it. I vaguely remember reading on various forums that 800 - 1200 is a good range, and if it goes up to say, 1400, you better open the damper plate and cool it down.

But on one forum, not this one, I saw someone saying oh don't worry, they can go up to 1700.

And I don't know if the concern would be for the catalytic element or the refractory unit.

Is there a consensus opinion on this? If you have a suggested temp, can you tell me where you got it from? VC doesn't offer a place on the website for questions, they only refer you to dealers. I called a dealer and he said gosh, never really thought of that.

The problem now is that if I build a fire any bigger than about 1/3 the volume of the firebox, I can't control it. Unfortunately [unfortunately??] my wood is extremely dry. I put it in the cellar the year before, so I have 2 years worth down there right now. By the time I get to burning it, it's really really dry. And also unfortunately, most of it is not big chunks. On average I can get my hands around a piece, finger tips and thumb tips can touch. The smaller the wood the faster and hotter it burns, of course. I try to save the big pieces for overnight. And I cant put enough in to go overnight without overheating it. So I rely on getting up in the middle of the night to go pee [old man] and reload then. Still, it often goes almost out.

Thoughts?
 
I saw 1500º as the limit before the catalyst is affected in the Blaze King thread. 1400º seems a good safety limit.
 
Repeated exposure to temps over 1600F, results in the washcoat flattening (normally looks like English muffin under microscope), the causes loss of surface area and leads to peeling. Peeling away of washcoat take with it all precious metals and the combustor no longer has a catalyst. The combustor is then toast.