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Kelly, Appliance Technician
Category: Appliance
Satisfied Customers: 22265
Experience:  Highly accurate diagnostician with over 30 years experience!
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My fridge is constantly running. I've done a lot of diagnosis

Customer Question

My fridge is constantly running. I've done a lot of diagnosis work but haven't figured out.
Submitted: 2 years ago.
Category: Appliance
Expert:  Kelly replied 2 years ago.
Thanks for counting on us to help with your appliance problem. My name is ***** ***** I look forward to helping you! If the thermistors have been replaced, the issue has to be with the main control. That would also explain the lack of defrost. The control should toggle the defrost cycle every 12 hours of compressor run time, regardless of temperature, so the control is faulty and will need to be replaced.

The control is shown as number 6 in the diagram below.

The link below is to the part you will need from a highly recommended company rated A+ with the Better Business Bureau. They offer a 100% money back guarantee, EVEN ON INSTALLED ELECTRICAL PARTS, for an entire year! They are the only company to allow returns on installed parts for a refund and offer a FULL ONE YEAR WARRANTY!


Please let me know if you have additional questions or need clarification. There is no additional charge for any follow up help!

Please remember to leave positive feedback before you leave. If you have any other questions, please let me know! You may continue asking follow-up questions until you have all the information you need, even after rating my service. Thank you!

Customer: replied 2 years ago.

I've done a lot of research on this problem. I found some expert said it may be because of lack of refrigerant. Let me know what you think. Here's what he said:

If you turned it off for a while and now you have frosting to a section of the fridge evaporator it's most likely to be short of refrigerant. Thermostats don't fail from being left off. On the other hand small suction side leaks turn into big leaks when the fridge is turned off and system pressures equalise.

You'll need someone to look at it to ascertain if it's short and where the leak is before recharging it. The reason they run all the time is the thermostat senses the last section of the evaporator. As there isn't enough refrigerant to remove heat from that section it stays warm and the fridge continues to run. Freezing stuff as a consequence.

Expert:  Kelly replied 2 years ago.
If it was low on refrigerant, it would not get below 0* F in the freezer. Furthermore, regardless of temperature, the control is programmed to shut the compressor off at 12 hours of compressor run time and initiate a 21 minute defrost. If it is not turning off at least every 12 hours of running, it can only be a control issue.
Customer: replied 2 years ago.

"regardless of temperature, the control is programmed to shut the compressor off at 12 hours of compressor run time and initiate a 21 minute defrost."

The above words gave me great confidence on your diagnosis! I'll order and replace it and let you know. Thank you!

Expert:  Kelly replied 2 years ago.
Sounds good, thank you!
Customer: replied 2 years ago.

Hi Kelly,

I placed the order but I thought of another question. In my understanding, the heater is controlled by thermostat, which is triggered by temperature. If the temperature is below a certain level, the thermostat's short so heater's turned on and then off after temperature's up. According to your answer, the control can also override the thermostat at an interval of 12 hours to turn on the heater. If so, there must be a separate circuit to do that. In other words, both the thermostat and the control can switch the heater on/off separately. Is my understanding right? Thanks.

Expert:  Kelly replied 2 years ago.
The control is the thermostat, it is what turns the compressor on and off. There is no separate thermostat.The defrost thermostat is in line with the heater to protect against an overheat but it is just a temperature controlled switch. If the compressor is not shutting off in 12 hours, it has to be a control issue.
Customer: replied 2 years ago.

I replaced the control board but the problem's still there. I defrosted it again and then the temperature of freezer dropped to below 0 F again because the compressor is still just constantly running. However, I noticed that if I manually stopped it by unplugging the power cord and then plugged it back immediately, the fridge didn't start right away. It started running after 10 mins or so (I don't believe the temperature would rise back to the level to trigger the motor in that short time though). Once it started running, it wouldn't stop... I know this is weekend but if I don't get a solution or instruction for the next step, I'll have to buy a new one since people can't live without it in summer...

Expert:  Kelly replied 2 years ago.
The starting delay is due to the compressor overload. The compressor will build pressure and it has to level out before it will restart. Did you allow it tor run for at least 24 hours to see if it stopped in 12 hours? Did you replace it with a new control?
Customer: replied 2 years ago.

Yes, I replaced it with a new one. I had it run for overnight, which was longer than 12 hrs but less than 24 hrs. I set the temperatures pretty high on purpose, like 5 and 43 F for freezer and refrigerator because I wanted to see if it could stop by itself but it reached to -4 F and still running! I don't think we found the problem.

Expert:  Kelly replied 2 years ago.
Did it shut off at 12 hours for the defrost cycle?