Went and fired up my old ILT 5500 Argon Ion Space Heater...err.. laser and it ended up doing a thermal shutdown because the fans never came on, they are switches on by a thermostat on the anode bell. Tried tripping it with a heat gun but no go. Pretty generic Airpax 5003 bimetal thermostat but the numbers on the back dont match their current scheme, 043-464. Anyone have an idea what temp these should kick the fan on at?