I have to agree sounds like a failing converter though I have no clue as to why the GFCI breaker has anything at all to do with it.
UNLESS it's on that circuit.
YOu say the fan never comes on.. The fan is controlled either by a straight bi-metal thermostat or more likely by an electronic "Driver" that feeds it different power levels depending on how hot the converter is.. My guess is the driver failed... If that's the case there may be a "Cheat" but.... Well. a progressive Dynamics 9200 is a good plan (Unless the converter is part of the power distribution panel then a 4600)
