Hi all i'm new to the forum just looking for some quick advice. I have a 18 month old Whirlpool bottom mount fridge / freezer. I have frost build up on the coils behind the back panel in the freezer. This is causing a blockage over time to the fridge causing it to get warm. I know this is a fairly common problem as I have seen numerous threads on this topic. My question is this, I have already checked the ohms of the bimetallic thermostat (when frozen) and came up with a reading of "0". I then checked the ohms of the defrost heater and came up with a reading of "30". To the best of my knowledge this fridge have a defrost timer that is electronically controlled by the main board that is in the fridge area mounted near the fridge/freezer adjustments. I am going to assume now that this board needs to be replaced. Does anyone know of a way to check the board? I have also already attempted to bypass the thermostat (when frozen) but couldn't get the heater to kick on....Any help would be greatly appreciated.

Denman thank you for your help! I am able to get the fridge to defrost using your instructions but only after cutting power to the fridge and then plugging it back in. The unit still fails to defrost on its own though. I am going to assume at this point since the heater does work and the thermostat is completing the circuit that the board is bad. Would that be a good assumption? I am only able to force a defrost cycle one time before having to unplug the fridge and then plug it back in to force another defrost cycle....does this sound normal?