GFA Thermal Switch Testing & Replacement - Desa

GFA Thermal Switch Testing &Replacement

Thermal Switch•The thermal switch is part of thesafety system on gas forced airheaters.•If operating properly, the switchwill shut off the heater if an overtemperaturesituation (such as theheater running with the fan off orunplugged)•If faulty, the switch will causeunexpected shutdowns.

Tools Needed•5/16” N utdriver•1/4” N utdriver•3/16” N utdriver•Philips screwdriver•3/8” O pen-endwrench

Getting Started•Make sure the heater isdisconnected from its gassupply and unplugged.•Remove the screws holdingthe fan in place. There are twoon either side of the heater anda third in the rear of the handle.

Disassembly• Remove the fanfrom the back ofthe heater and setaside.• We now haveaccess to thethermal switch onthe back of theburner head.

Removing the thermal switch• U se your 3/8” and 1/4” nutdrivers to remove the boltsand nuts that hold thethermal switch in place• Disconnect the switch fromthe two blue wires thatconnect it to thethermocouple assembly.

Bypass test•Set the thermal switchand screws aside•Remove one of the twoblue wires and set aside;loop the other blue wireto the other spade,completing the circuit.

Caution!• Plug the fan in firstbefore igniting theheater. Turn the gasoff before unpluggingthe heater. Failure tofollow these steps willcause a flame thatburns on the backsideof the burner head,damaging the wiringand thermal switch.

Testing• If the unit runs as itnormally should, thethermal switch needs to bereplaced.• Operation without theswitch is for testingpurposes only – do not usethis heater without thethermal switch in place

Testing cont.• If the heater still shutsoff and does not runcorrectly there could be aproblem with thethermocouple or thevalve.• Contact DESA heatingtechnical services at 1-866-672-60406040 for furthertroubleshooting.

Desa Heating LLCThank you!