A customer called us and complained about his refrigerator GE Monogram ZFGB21HXCSS not cold. They experience weird behavior from this unit he worked for one week then stop for another. Also, they had a loud grinding noise coming from the unit. So they decide to use my company for repair. I inspect the unit and notice frost build up in the freezer. For me, it looked like defrost issue.
I removed the freezer door, racks, icemaker, all sliders and back wall to have access to internal parts. GE they don’t make life easy for service techs the use most complicated design to disassemble the compartments so it usually takes a while to do it.
The evaporator coil was completely clogged with ice. Frost buildup become so big that he was touching evaporator fan blades. That’s why they had this annoying grinding noise.
Using the steamer I removed the frost build up. Now I conducted several tests for defrost cycle components and find some bad parts. I replaced the defrost thermostat and temperature sensor for evaporator coil. Bad temperature sensor on the evaporator coil is a very common issue for GE appliances. This sensor is mounted on the evaporator coil itself and experiences extreme temperatures changes multiple times a day. At some point, he just provides control unit with wrong information, that temperature in the unit is warmer and control unit force compressor to work more. Extensive runtime means more frost build up on the evaporator coil. Plus to that, in this case, we get bad bimetal thermostat which finished defrost cycle too soon. As a result, the defrost cycle was not long enough to melt down frost build up on the coil.
Heating element had passed the continuity test so I didn’t replace him. After I installed the back wall and all components which I had removed before. I also conduct several tests to make sure that the system works as suppose to.
Another happy customer!
