Whirlpool fridge WRT541SZDM01 Compressor and fans run continuously

Brand: Whirlpool
Model Number:WRT541SZDM01
Main Symptom: Compressor and fans run continuously. Defrost heater failed. Related?
What happens & when:

Error Code (if any):
Parts or tests already tried:
Photos / video link:

If the defrost heater has failed then this would certainly cause the compressor and fans to run continuously. A defrost problem causes the evaporator to ice over and will cause the unit to have to run longer trying to get the unit down to temperature.