Question: Background: In 1990 we installed a new Vermont Castings Winter Warm system (with the energy cabinet)in our home. We have used it since 1991. We have used the Winter Warm a lot(sometimes running 24 hours a day). We have replaced the gaskets on a regular basis and cleaned/replaced the catalytic converter which fractured and dumped the loose elements almost every other year. Last year, we removed the catalytic converter, since it was too expensive to continue to replace (with the expressed approval from our dealer). We were told that it would be less efficient and therefore use more wood for the same amount of heat and the pollutants would increase some, but that was all. Problem: The upper and lower fire back of the winter warm has become severely warped, to the extent that the damper doesn't close! We have therefore had to purchase new parts for $165. We elected not to buy a new catalytic converter ($150) because of the failure rate and cost. Question: Does the temper in cast iron change over the years with constant, but not abusive use, to the extent that it becomes malleable? It seems like the stoves/fireplace inserts would have been designed to operate for many years without part failure of this kind. The cost advantages of using wood goes up in smoke under these circumstances! Has anyone else complained of this problem? Answer: Ken, a few comments... 1. The dealer was wrong for telling you that you could remove the cat..This is against EPA regulations. Removing it allowed the stove to burn hotter which may have caused the stove to warp. 2. The cat has a 6 year pro-rated warranty, which should have allowed you to replace it at a reduced cost. 3. Cast Iron is the best material for such a use..however, repeated cooling and heating can warp it or wear it out. Parts replacement should be considered normal. If you look at the $165 over the 6 year life of the unit ($30.00 per year) it does not seem like an excessive maintenance cost....I spend 1200 or more per year keeping my 1992 Van running (with new brakes, etc.). I've used oil and other fuels in my house and have spent hundreds of dollars per year in servicemen, etc...so I don't think that any fuel is without it's problems. Hope that helps.