John, I have been readig your posts and I too have had good luck replacing my own parts. I have replaced the pump cartridge several times, (you would think they could make the impeller out of material strong enough to last). I now have a problem with the combustion blower making a lot of noise.This has happened before about 5 yrs. ago. The dealer who used to handle the parts here locally (Detroit Area) is no longer available. Looked on line but haven't found any which are reasonably priced.Any suggestions?