The elements rarely go on these . If there is no lights at all on the thermostat then it will be the power control module ( attached to the on off switch on the lower side of panel heater interior) Do not confuse this with the other circuit board in the the themostat at the top of the heater . You can test this part is faulty by substitution of known good parts from another RF heater that is working OK . All that is needed is a posi screw driver and a bit of care and common sense when dismantling.Isolate power before proceeding .do not attempt if incompetent with electrics - usual disclaimers apply !
