Whirlpool WP10428409 Defrost Heater (Evaporator) OEM Part

After doing some research, I guessed it was either a faulty defrost timer, defrost thermostat, defrost heater, or some combination of those. Using part location diagrams for my Amana BC120TW I started by looking for the evaporator coils since they obviously weren't producing enough cold. Upon removing the evaporator coil cover, I found the evaporator coils frozen into 1 solid block of ice. Using a heat gun, I carefully defrosted the coils so I could access the defrost thermostat and heater for testing. The thermostat was obviously in need of replacement since it appeared water had frozen inside of it and caused it to pop open. The heater also did not pass a continuity test making me think it was also broken. However a little more research on defrost heaters told me not all heaters will pass a continuity test, but will have an ohm reading. The old heater tested out at 29.8 ohms while the new one from AppliancePartsPros tested at 30.2 ohms. Since they were essentially the same, I knew the heater was still good. The only thing left was the defrost timer which I replaced since it was the original electro-mechanical part containing a motor and timer mechanism, and also the cheapest part to replace. I don't know whether the defrost thermostat went bad preventing the defrost heater from working, or whether the defrost timer stopped working again resulting in the defrost heater from working and freezing the thermostat. In any event, I have a new defrost timer and thermostat and a refrigerator that is back working as it has for the past 25 yrs.

Grateful to have Appliance Parts Pros around with the parts in stock. Great customer service and the ordering went real smooth, thank you. Took freezer interior parts out and relpaced defrost heater, defrost timer and in line defrost thermostat. So far it has been working perfect.