Roper Refrigerator Compressor Running Constantly, Not... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) sends a 120V AC signal to the compressor relay based on temperature sensor readings. If the sensor is faulty or the MCU logic is incorrect, the compressor can run constantly. Voltage paths include the breaker panel, power cord, wire harness, MCU, compressor relay, overload, and compressor windings.

Symptoms:

The homeowner observes that the refrigerator compressor is running continuously, making a humming or buzzing noise. However, the refrigerator is not cooling properly; food is not staying cold, and the freezer is not freezing items effectively.

Possible Causes:

Refrigerant leak
Faulty start relay or capacitor
Defective compressor
Clogged or restricted condenser coils
Damaged or inoperative evaporator fan motor

Solution:

1

Unplug the refrigerator or turn off the breaker to the refrigerator circuit at the breaker panel.
2

Check the condenser coils (usually on the back or bottom). Clean them thoroughly with a vacuum and brush. Re-energize the refrigerator and monitor for temperature change for 24 hours.
3

Access the start relay and overload. Use a multimeter to test the start relay for continuity. Replace if defective.
4

Check the voltage to the compressor using a multimeter. It should read approximately 120V AC when the compressor is attempting to run. If no voltage is present, check the control board or wiring.
5

Check the evaporator fan motor. If it's not running, test for voltage using a multimeter, if the voltage is correct replace the motor.
6

If the above steps fail, a sealed system issue (refrigerant leak or compressor failure) is likely. This requires specialized tools and expertise; consult a qualified refrigeration technician.
7

If the compressor is running but the high-side pressure is too low and the low-side pressure is too high, there is a good chance that the compressor valve is leaking. It's likely time for a new compressor or refrigerator.

Safety Warning:

Always disconnect power to the refrigerator before performing any repairs. Use proper Lock-Out/Tag-Out (LOTO) procedures to prevent accidental energization. Be aware of high voltage present in the electrical components of the refrigerator.

Prevention:

Clean the condenser coils every 6 months to ensure proper airflow. Avoid overpacking the refrigerator, which can restrict airflow. Check door seals regularly for leaks and replace if necessary.

Expert Tip:

You can sometimes force a defrost cycle by pressing and holding the freezer temperature down button and the refrigerator temperature up button simultaneously for 10 seconds. This may help identify if the defrost system is the root cause.

Frequently Asked Questions

•How do I access the start relay on my Roper refrigerator?

The start relay is usually located near the compressor. You may need to remove a panel or access it from the back of the refrigerator. Use a 1/4-inch nut driver to remove any screws.

•What refrigerant type does my Roper refrigerator use, and how can I tell if it's leaking?

Most modern Roper refrigerators use R134a or R600a refrigerant. A refrigerant leak is difficult to detect without specialized equipment. Signs of a leak may include frost buildup on the evaporator or a lack of cooling performance. A qualified technician can use a refrigerant leak detector to pinpoint the source.

•How do I test the evaporator fan motor?

First, ensure the fan blades are not obstructed. Disconnect the power to the refrigerator. Locate the evaporator fan motor, typically behind a panel in the freezer compartment. Use a multimeter to test the motor windings for continuity. If there's no continuity, the motor is likely defective. You can also apply 120V AC directly to the motor (with extreme caution and proper safety measures) to see if it runs.

Roper Refrigerator Compressor Running Constantly, Not Cooling: Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the start relay on my Roper refrigerator?

•What refrigerant type does my Roper refrigerator use, and how can I tell if it's leaking?

•How do I test the evaporator fan motor?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: