My whirlpool side by side started warming up on refrigerator side and top of freezer was defrosting as well.
I pulled the panel off the coils and found a block of ice. So, turned the refrig off and let it defrost over night. I was using this site for where to begin troubleshooting.
The next day, I found the tech sheet and used it to initiate a force defrost cycle, and waited for relay click as it said but the heater did not turn on at point.
Now my question is did the heater not turn on because at the point the coils were not cold and thermostat did not allow? Or should it have come on regardless of temp, since I forced it.

Second question, when you force defrost cycle does that actually by pass the control board? Or since I heard the relay click, does that mean the control board is sending signal and therefore not faulty?

Trying to determine which of the 3 parts are faulty and don't have a multi-meter on hand but going to pick one up.