Hey Mandoo and Moondoggy, maybe you can help bmwbj out here since you both run VC cats. BJ, as you describe it, your case certainly does seem "mysterious". Two things occur to me as possibilities; first, you're exposing your cat to such high flame temps that you might quickly be damaging it, and secondly, you might be poisoning it if you use any newspaper with color print in it to start your fires. Essentially in running a cat stove, you simply need to reach and sustain 500 degrees in the gas stream feeding through your cat to light it off. Once it is lit off, which you can tell by the dissapearance of smoke ftom your stack and by rising griddle temperatures, you will start to reduce the air supply and the cat will stay lit as long as there is a smoke supply for it to feed on regardless of whether the firebox temps drop below 500 degrees or not. This is why cat's can provide such long burns because you can run your stove very low, even at a smolder, and the cat just fires off the smoke. To me it seems that trying to light off your cat at 700 degrees risks exposing it to very hot flames for a long time before you engage it which might damage the cat, but also your box temps are so hot that you are getting pretty complete combustion the old fashioned way leaving little in the gas stream for the cat to combust. I'm assuming you are correct in saying your flue is perfect though I think draft issues are very important in all of the EPA stoves and I'd like to know your chimney set up. You also say your wood is not a problem though cat's do need a nice dry wood supply to run their best. You say it runs great until you engage the combustor. Engaging the combustor does reduce the air flow a bit but that is the essentially the only change to the stove's air flow operation and in itself would seem not to explain the smoke that results. If you are damaging your cat from poisoning it or from flame impingement, it would seem to me possible that when you engage the combustor, the combination of reduced air flow with a lack of light off would then result in substantial smoke from your stack. If you want, PM me and we can go over all the procedures and get you stove working the way it's designed to. Even with the quality issues VC has had, it doesn't seem to me that is what the problem is. Not knowing the real details of air flow in the VC cat stoves, the only other thing that occurs to me is a problem with it's secondary air flow.bmwbj said:
