Freezer working pretty good but fresh food(bottom) not cooling properly. Frost forms on back wall of freezer but does defrost. Have replaced thermostat, but still having original problem. Is it the defrost timer? Fan in freezer works.
This issue would most likely be caused by a bad defrost heater or the timer. You can check to see if the heater is good by turning the defrost timer until it clicks an then check to see if the heater is coming on. If the heater does not come on then the heater is most likely the cause and if heater does come on then the defrost timer would be the cause.
After the defrost I reassembled the refrigerator back and it actually worked better for a month then frosted back up. I checked the heater piece for continuity and the meter beeped so I take it as good, wasn't sure how to check the defrost thermostat on the coil, or the defroster control in the main compartment behind the unit. Also, how do you check the defrost control unit? Thank you.
Answer Hello Frank,
You need to begin the troubleshooting process with the unit frosted or at least after you let it run 24 hours. This is because the defrost thermostat can only be tested when it is below 20°F. Open the fresh food door and look at the control enclosure for a hole about 1/2 inch in diameter, (usually straight up). There will be a plastic "knob" inside the opening that can be turned with a small screwdriver. This is how the unit is advanced into the defrost cycle. As you turn it, you will hear it clicking. When it gets to the defrost cycle, it will click louder. Stop at this point. This is the beginning of the defrost cycle. Close the door and wait about two minutes. Now open the freezer compartment and look for an orange glow from the bottom "air grill" in the back wall of the freezer. If you see the glow, the defrost heater is energized and the issue is the defrost timer. The heater and defrost thermostat is verified good if the glow appears. If you don't see the orange glow, you need to remove the rear wall of the freezer compartment and test each side of the defrost thermostat for the 120Vac. If the voltage is on both sides of the defrost thermostat, it is good and you will need to use a resistance meter with power off to the unit to test through the defrost heater. Once you have located the bad part, you should allow the unit to sit in defrost with the unit plugged in for at least 45 minutes to make sure the timer cycles back out of defrost. This makes sure the defrost timer motor is good and advancing the timer properly.