I am not sure what happened. Last year i ran my stove none stop for almost the whole winter without problem. I had a problem this year, i over fired the stove. it wasn't that bad, and i looked afterewards and the stove looked fine. then like a month later i started having problems keeping the house warm. there is a crack in the one firebrick, but was told no big deal just get it replaced next time the stove is down for a while. When i called the dealer about my stove he had me take temp of the stove top(500), and of the pipe(250). He said it sounded good. He thought that the problem is that it is just to cold for the stove to keep up. It was a cold week when I called but nothing that my stove couldn't handle before. So now i am looking for some thoughs on my problem. Any ideas would be great, Thanks