We have a problem with fan coil units having a "Dirty Sock" odor problem. This odor starts when a a unit switches from heating to cooling mode. The probelm is only when the unit changes from an extended period of heating over to cooling and seems to last only 15 to 20 minutes into the cooling...
I second the comment on silicon carbide. I have had a silicon carbide H.S. ignitor in my furnace for the last 13 years. I have had to replace it three times and they are very deilcate.
