Brand: whirlpool fridge Model Number:WRF757SDHV02 Main Symptom: not defrosting and diagnostics service test 6 shows bi-metal is open What happens & when: a month ago and it works well after defrosting manually with heat gun but problem came back when ice is formed around evaporator coils.
Error Code (if any): service test 6 - 02 : bi-metal is open
Parts or tests already tried: defrost heater, evaporator fan/thermostat and air baffle motor are tested good. Relay K6 on control board replaced.
Photos / video link:
If test 6 is showing 02 Open with the evaporator frozen over I’d keep it on service test 6 and check voltage at the P2 connector Pink wire to Brown wire on the main board W11161172 in the back.
If you’re getting 120v AC then the bi-metal/thermostat circuit is open. At that point you’ve either got a bad thermostat or a wiring issue in that circuit.
If you’re not getting 120v, you’ve got a bad board, either it isn’t putting out voltage or the board itself just isn’t reading correctly.
thanks for the troubleshooting tip. how do I get the multimeter probes to the P2 connector? The pink to brown wire is wired to the connector as shown in the attached pic.
You should be able to get your meter leads in through the back of the connector. I didn’t think about it yesterday, but you could do another check for continuity instead of voltage if the evap is frozen over. Unplug the fridge, disconnect P2, and take a continuity reading between brown and pink. If the evap and bi-metal are frozen over, so around 0 degrees, then you should be reading very near straight continuity.
If so then the bi-metal is closed and the board is bad, if not then you’re back to either a bad bi-metal or the wiring in the bi-metal circuit.
I tested the bi-metal thermostat and it showed continuity at -11 degrees C.
I manually defrosted the evaporator coil with a heat gun and after that the diagnostic test 6 showed 01 which is closed but went back to 02 - open after a couple of days. Should I replace the control board? I was told relay K6 on the control board is for the defrost system and has replaced the relay.
Replace the control board, the bi-metal is closing and everything seems to be checking out in diagnostics mode, so that would be a logic issue on the main control.
