Common Causes of Refrigerator Compressor Problems
The refrigerator compressor is the heart of the refrigeration system. It is responsible for pumping refrigerant through the system to remove heat from the refrigerator interior and release it outside. Some common causes of refrigerator compressor problems include:
- Refrigerant leaks: If the sealed refrigerant system develops a leak, the level of refrigerant can drop below the amount needed to effectively cool the refrigerator. This causes the compressor to run constantly as it tries to maintain the proper temperatures.
- Faulty components: Issues with components like the capacitor, relay, or overload can prevent the compressor from starting up properly. This leaves the refrigerator without cooling.
- Electrical problems: Problems with the electrical supply, wiring, or components can prevent the compressor from receiving power. The compressor needs consistent power to run and cycle on and off as needed.
- Dirty condenser coils: The condenser coils on the back or underneath the refrigerator remove heat from the refrigerant. If they become clogged with dust, pet hair, or debris, they cannot effectively release heat and cool the refrigerant. This puts extra strain on the compressor.
I’ll go into more detail on each of these common compressor problems and how to diagnose them in the sections below.
Detecting and Fixing Refrigerant Leaks
Refrigerant leaks are one of the most common reasons a refrigerator compressor may stop working properly. Here are some ways to detect and fix refrigerant leaks:
- Check for visible damage to refrigerant lines that run along the back of the refrigerator. Punctures or cracks can cause slow leaks. Carefully inspect and seal any leaks.
- Listen for a hissing sound near connections between refrigerant lines or components. The sound indicates escaping refrigerant. Have a technician locate and repair the leak.
- Conduct a leak test using fluorescent dye and a UV light. The dye will glow at the site of any leaks. An HVAC technician can perform this test and make necessary repairs.
- Monitor performance over time. Slow leaks may cause the refrigerator to gradually lose cooling capacity. Have an HVAC technician test refrigerant levels and charge the system if low.
- Replace faulty components like old valves and fittings that can develop leaks over time. Preventative replacement can avoid bigger leaks down the road.
Repairing refrigerant leaks is crucial for ensuring the compressor can effectively circulate refrigerant and cool the interior. Neglected leaks will cause compressor failure.
Checking Capacitor, Relay, and Overload Issues
The capacitor, relay, and overload work together to start the compressor and keep it running. Here’s how to check them:
- Use a multimeter to test the capacitor. It should be fully charged but may lose this charge over time and fail to start the compressor. Replace if faulty.
- Check that the relay clicks when the compressor tries to start. No click indicates a bad relay that needs replacement.
- The overload protects against overheating. It can cut power if tripped. Reset the overload and test compressor operation. If it continues to trip, have a technician inspect the system.
Replacing bad capacitors, relays, and overloads will get the compressor back up and running if they have failed.
Checking Electrical Supply to the Compressor
The compressor relies on consistent electrical power. Some things to check include:
- Power cord connected securely to outlet and refrigerator
- Voltage at the outlet – should be 110-120V
- Continuity of wiring from outlet to compressor
- Good contacts in the compressor Electrical problems are best left to an appliance repair technician to diagnose and fix.
Cleaning Dirty Condenser Coils
Dust and debris on the condenser coils blocks airflow and prevents proper heat dissipation. To clean them:
- Unplug refrigerator and pull it out from the wall.
- Use a vacuum, brush, or compressed air to remove dust buildup on coils.
- Clean fins of debris using a crevice tool. Avoid damaging fins.
- Replace cover and plug refrigerator back in after cleaning.
Proper condenser coil cleaning every 6 months helps the compressor run efficiently. Neglected condenser coils are a common cause of compressor failure.
Troubleshooting Refrigerator Cooling Issues
If the refrigerator compressor is running but the interior temperatures are not cold enough, there are several things to check:
- Airflow obstructions in the refrigerator and freezer compartment
- Failed thermostats that aren’t calling for cooling
- Refrigerant flow restrictions caused by a blocked capillary tube
- Evaporator fan failure prevents air circulation to remove heat
- Defrost system problems that allow frost buildup and poor cooling
Below are some steps to troubleshoot common refrigerator cooling problems:
Inspect Airflow in Refrigerator Compartments
Ensure cool air can circulate properly:
- Move items away from vents so air can flow freely
- Make sure items aren’t packed too tightly on shelves
- Check and clean refrigerator and freezer fan/ventilation ducts if present
Removing obstructions can improve cooling capacity if airflow is blocked.
Test the Thermostat(s)
Use a multimeter to test the continuity of the thermostat:
- Adjust temperature setting below current temperature
- Check for continuity across thermostat terminals
- Replace thermostat if no continuity with temperature set below interior temp
The thermostat must call for cooling when the temperature exceeds the thermostat setting. Replace faulty thermostats.
Check for Restrictions in the Refrigerant System
A clogged capillary tube won’t allow proper refrigerant circulation:
- Only a technician can inspect and replace a restricted capillary tube
- Signs include cooling in the freezer but not refrigerator compartment
Have an HVAC technician determine if the capillary tube needs to be replaced.
Ensure Evaporator Fan Operation
The evaporator fan circulates cool air:
- Inspect fan for broken blades or obstructions
- Check if fan has power but won’t run – may need a new fan motor
- Replace fan cover, housing, blades, or motor as needed
Restore evaporator fan operation to maintain proper air circulation and cooling.
Inspect and Repair Defrost System
The defrost system prevents ice buildup on the evaporator:
- Check that defrost timer advances and terminates defrost cycle
- Test defrost heater and thermostat if frost buildup occurs
- Replace bad defrost system components as needed
Proper defrost allows for full cooling capacity. A technician can diagnose defrost issues.
Summary
- Refrigerator compressors fail due to leaks, electrical issues, faulty components, and dirty condensers
- Refrigerant leaks should be identified and sealed to prevent compressor failure
- The starting components – capacitor, relay, overload – should be tested and replaced if faulty
- Electrical supply to the compressor should provide consistent 110-120 volts
- Condenser coils need to be kept clean of dust buildup for proper operation
- For cooling issues, check airflow, thermostats, refrigerant flow, evaporator operation, and defrost system
Being able to identify and fix the most common compressor and cooling issues can help extend the life of your refrigerator and keep food properly chilled. Call an appliance technician for diagnosis if needed.