Refrigerator compressor not running

Why is my refrigerator compressor not kicking on?

The compressor circulates refrigerant throughout the cooling system, so if your refrigerator’s not cooling, the compressor or components that work with the compressor could be to blame.

Learn how to check the start relay, which activates the compressor, the electronic control board, which sends power to the compressor and the wires that connect the two by watching this safe DIY troubleshooting video:

Check the start relay

Remove the machine compartment cover on the back of the fridge and check the condenser fan.

If the condenser fan runs, then your compressor should be getting power because the compressor shares a circuit with the condenser fan motor on most refrigerators.

Follow these steps to check the compressor start relay:

1. For safety, unplug the refrigerator.
2. Unhook the retainer clip and pull the PTC start relay out of the refrigerator.
3. Shake the start relay to see if it rattles.

If the start relay rattles when you shake it, that's a tell-tale sign the relay is fried.

Replace the start relay.

If the start relay doesn't rattle, you’ll need to check for continuity to confirm that it’s bad.

Put the one meter lead into terminal 5 and the other meter lead into terminal 6.

If you detect an open circuit between those terminals, then you’ll need to replace the PTC relay.

If the start relay's okay, then you may have a defective compressor. Unfortunately, you’ll need to get a service technician’s help to replace a compressor, because that repair involves recovering Freon.

Check for thermistor problems

If your condenser fan wasn’t running, then you may have a defective electronic control board or a bad thermistor (also called the temperature sensor), two problems we can often help you diagnose and fix. Many refrigerators have a diagnostic test mode to check refrigerator operations.

To enter the diagnostic test mode on the model shown in the video, press the light switch 3 times, then press and hold it a 4th time until you hear a long beep. You're now in the test mode. If this doesn’t work on your model, check your tech sheet for instructions. You can usually find it located behind the bottom front grill or taped to the back of the refrigerator.

In this test mode, press the door switch twice to start the compressor. The control beeps twice and then you should hear the compressor start. If the compressor runs in the diagnostic test mode, you’ll need to check the thermistor, also known as a temperature sensor. A bad thermistor prevents the compressor from running in normal operating mode. The diagnostic test mode forces the compressor to run whether the thermistor is broken or not.

This video will show you how to further diagnose a broken thermistor:

Check the compressor and wiring

If the compressor doesn't start in the diagnostic test mode, you’ll need to check continuity from the electronic control board through the compressor circuit.

If you measure around 5 ohms on the meter, it means you have continuity.

If the compressor circuit shows continuity, you'll probably need to replace the electronic control board because the board is not sending voltage through the circuit to the compressor.

If the compressor circuit is open, look for pinched or broken wires in the control board harness and on the wires leading up to the compressor. Repair or replace any broken wires that you find.

If wiring is okay and the start relay wasn't the problem, you’ll need to have the compressor replaced.

What to expect when you experience a refrigerator compressor not running issue

Solutions to a compressor not running problem

Resolving most compressor not running problems usually involves replacing the compressor, electronic control board or evaporator. However, there are many potential causes. Thorough troubleshooting and an accurate diagnosis are crucial to effectively fixing the problem.

Recommendations for a refrigerator compressor that is not running

When your refrigerator compressor is not running, there could be several reasons. To avoid replacing unnecessary parts, we recommend having a professional experienced in diagnosing all types of refrigerator failures perform diagnostic tests. This will help identify the root cause of the problem and efficiently resolve the issue for you

What to consider with a refrigerator compressor not running diagnosis

Effectively diagnosing malfunctions in modern appliances necessitates a comprehensive understanding and specialized training. Addressing refrigerator issues without employing precise diagnostic techniques may lead to ineffective repairs and unnecessary part replacements. With significant advancements in appliance technology over the past decade, contemporary models now feature intricate electronic components that pose considerable challenges for troubleshooting. Consequently, do-it-yourself repairs on modern appliances have become increasingly intricate.