heater coils broke, thermostat sensor open, there are 2 or 3 sensors ontop of the heater channel, some are resetable with a pin though the small hole in the back of the sensor, some are not, some reset themselfs, some are not resetable, when u look at face of the sensor, it should dome out slighly, dont be tempted to push the dome in, if u do and it stays in, u will have to buy a new one, unless theres a pin hole in the bk. dont push a pin in the hole with unit pluged in. to test a thermostat sensor take off one spade clip and test with a meter on beep, if u hear a beep across the 2 two tags then its good, no beep, no good.
mark simon smith
January 2015