Anybody have an Appalchian insert made in the early 80's or late 70's that uses combustors?

[JMartin]

I have an early 80's 32B with crumbling combustors. Debating on putting in new ones along with a cat probe.

 

[central_scrutinizer]

I have an early 80's 32B with crumbling combustors. Debating on putting in new ones along with a cat probe.

You should definitely replace your combustors if they are crumbling. Your stove will not operate as designed without functioning combustors. You will get much more heat output, not to mention much linger burn times. A cat probe is a very good idea so you know exactly how to adjust your draft to keep the cat at optimal temperature. Well worth the $30 bucks.

 

[JMartin]

Thanks CS. I was hoping to find someone that had this insert but I suppose other brands are pretty much the same in function. I'm trying to understand how the cats work. I'm not sure that I run my stove hot enough to keep them engaged. I understand that you need to get them up to temp (400-600) before engaging but what happens after that is pretty foggy. I know that the cats burn the smoke and that helps keep them firing but isn't there a point where the stove can just get too cool to keep the cats going? Does the internal temp of the stove have to stay at least 400? I try to keep the air coming out of my stove around 250. And how do you clean the cats? Mine are held in the top of the stove by a cast iron cradle that I have to use a bottle jack to lower once I remove the bolts because of the weight. And how do I keep the flames from making contact with the cats as I understand that can damage them? If I put a cat thermometer in do I have it make contact with one of the cats or with the cradle or just have it close to it? Is it durable enough to be left in place or do I just use it as a check once in awhile and use the surface thermo to monitor? Or am I just making this way more complicated than it needs to be?

 

[JMartin]

You know what I'd like to see is a timeline of a typical cat in operation. Maybe a plot of the cat temperature over time as certain things happen along with a reference temp, say on the top and/or inside of the stove. You would see the stove temp track the cat temp to a certain point and then the cat would take off. At certain points along the line you would see the affect of opening or closing the air controls and reloading the stove. Towards the end I guess you'd see the cat temp drop to meet the stove temp.

 

[mellow]

Surprised to find this in the classic forum, you have an EPA stove if the stove came with cats.

My cats light at around 500 using the Condar 6" cat probe, they stay lit with a full firebox for about 8-10 hours before the cats drop below 450 degrees.

Once I get my wood good and charred on the bottom I close the damper at 500 degrees as per the Condar cat probe, then I will turn my air to half for about 5-10 minutes then fully shut my air intakes after that. If I want to keep a good amount of heat going I will crack open up the air intakes slightly, I also have to do this in the fall with warmer weather or I get blowbacks.

 

[JMartin]

Thanks, Mellow. I don't know how old this stove is, I can't find anything that tells me when this model was made. Would you like to take a stab at it? Also, where is the tip of your cat probe positioned - just in front of the cat or does it make contact with it? Do you leave the cat probe in all the time? How do you clean your cats?

 

[mellow]

My probe sits on top of the left cat (2 cats). No idea about the stove itself, but it if it came with cats it is from the early-mid 80's. Probe stays in all the time. I use compressed air to gently blow out my cats.

 

[JMartin]

The title of the forum "Classic Wood Stove Forums Pre-EPA (prior to 1988)" is a little confusing then..I've been using compressed air as well and I thought that might be the reason for them crumbling (from thermal shock) or it could be from flame impingement (no shield on this model) . But then I have no idea how old these cats are. I've had the stove for 3 years. Do you look for a certain reading on your cat probe to decide when they're cool enough to clean? How often do you clean them?

 

[mellow]

I only cleaned mine once this past season, usual small buildup of fly ash on them, nothing affecting performance. I let the stove cool down for a day before cleaning it, the cats can be touched and my cat probe is as cold as it gets.

I would change your cats and fab up a cat shield, flame impingement will kill your cats quickly.

 

[JMartin]

If you get a chance could you take some measurements of your shield? Maybe I'll get lucky and it will fit mine..Would you say the center of the hole for your cat probe is in line with the center of the hole for the damper rod?