My Castile in the middle of the night started to make a really nasty noise. I concluded that it was the exhaust fan not the convection blower. I cleaned out the stove, and opened up cleaned the front part of the exhaust blower, now about to take off the side panel to clean. If this does not solve the issue, I might have to replace it. Who can suggest any possible extra tips? And or if if it is to replace the unit anyone suggest a good online parts dealer. My local dealer at least for a service call has a week to 10 days turn around time for repair so I need to do this myself. *edit* I also cleaned the exhaust pipe to make sure there was no blockage, all i could see was a small amount of black soot Also anyone know where you can get the "testing unit" for the castile, if it's not too costly that is.