We have had zero problems with ours but I believe that the motors are controlled directly from the ETC unit with no other relays. If the ETC is causing it due to under or over temp you should be getting a code on the readout. If the readout looks normal there is a tiny red dot that should be on when it is calling for heat, if you have never noticed it it is hard to discribe. Other things to check is the fan off switch pull the screws and check for voltage in and out of the fan switch, then at the motors them selves. Are the draft flaps opening? If so that points directly to a motor problem. There is a snap disk type over heat safety that must be manually reset. On the 4400 it is on the rear of the drum above the pumps. You can follow the wires under the blanket with your fingers and when you reach the reset push the button in. If it has tripped you need to find out why, air leaks at door gasket, draft flaps sticking open are two I can think of.