It's important to perform regular fridge maintenance before trying these fixes. Your appliance should last for at least 10-15 years before needing replacement, so keep it running well with these tips.
Safety Note: Power Down the Fridge
Before removing and replacing or continuity testing electrical components, power down the fridge. This will prevent damage to the components and prevent you from being electrocuted. Still, some electrical components — like capacitors — will store their charge and should not be tampered with.
- If the fridge is pulled away from the wall, or if the power switch is easily accessible, remove the plug.
- Otherwise, find the fridge’s circuit breaker in your breaker box and turn the circuit off.
- Verify your fridge has lost power by opening the doors and seeing if the fridge lights turn on.
Safety Note: Sharp Sheet Metal
When working underneath the fridge, consider wearing gloves to avoid cuts from the sharp sheet metal. The sheet metal is the thin structural metal where components mount. While wearing gloves may make work more challenging, it’s worth protecting yourself.
When refrigerators experience temporary power outages, they may enter a safe mode. The safe mode protects the fridge's internal components from electrical overloading. You'll have to reset the power to your fridge.
- Unplug your refrigerator. If the plug is too hard to reach, switch the circuit breaker off.
- Wait 5 minutes before returning power to the fridge.
- Once power is back, open your freezer and push the light switch 3 times to trigger a cooling cycle.
- Monitor temperature over the next 24 hours.
Incorrectly Loaded or Overloaded Fridge
The evaporator fan blows cold air around the freezer. Too much food or incorrectly placed food will block the vents and prevent proper temperature regulation. The refrigerator vents allow for airflow between the fridge and freezer compartments. The following tips may help your freezer maintain a safe temperature:
- Locate your evaporator fan and move frozen items further away.
- Unblock the vents. A rule of thumb for frost prevention is to stock enough food to fill the freezer while keeping an inch of space between the food and the walls.
Incorrect Thermostat Setting
View the knob or dial that sets the device temperature. Verify it is set to cold and hasn't been bumped or shifted positions. Your freezer should be set at zero degrees Fahrenheit (-18 degrees Celsius). Use a thermometer if you don't have a digital thermostat display. If the settings are ok, go on to the next item
Failing Door Seals
Door seals are gaskets for your fridge, and as they age and fall apart, cool air escapes through the cracks in door seals.
- Inspect your door seals, then clean or replace if necessary.
- Failed door seals will often lead to excessive frost, in which case the next step will help.
Excessive Frost Buildup
If your evaporator (the cold part inside the freezer) gets coated with ice and frost, it will stop airflow, which will cause the freezer and the fresh food area to warm. You will need to remove a panel inside your freezer to check this (you will have a chance to look at the evaporator fan as well when you remove the panel)
- Unplug or power down your unit
- Unload the freezer and carefully remove the ice that you can pick up.
- Remove the evaporator cover. Here are two guides for replacing the evaporator fan; they will show how to access the evaporator,
- Use a steamer to melt the ice buildup if present.
- Alternatively, you can place bowls of hot water in a position to melt the ice, but this is much slower.
- A hairdryer on a low setting can be used as a last resort, but even hairdryers can overheat plastic parts and cause warping. Do not use a heat gun, as overheating is much more likely.
- Lay towels in the bottom of the machine to absorb the water. Pay attention to the drain located below the evaporator (the part with fins and tubes) if you can remove the rear cover of the freezer.
- Completely dry the freezer before powering the unit back on.
If you have an auto-defrost unit, the accumulation of thick ice suggests some part of the defrost cycle has failed.
Dirty Condenser Coils
At the rear and underside of your fridge are the condenser and its coils. The refrigerant passes through the coils and dissipates heat during the cooling cycle. As dust and debris accumulate on the coils, the fridge becomes less efficient at removing heat, and the freezer temperature will increase.
- Pull your fridge out and inspect coils.
- Your fridge may have an anti-tip bracket and can only be removed by pulling straight out from the wall.
- Clean dust off condenser coils and fan with a stiff ++condenser coil brush++ and vacuum.
- Work carefully during this task and avoid bending or damaging the tubes.
- Clean the entire machinery compartment as well; otherwise, the increased circulation may just deposit new dust on the condenser from that area.
- Test the fridge and see if the problem has been solved,
- If the condenser was already ok, or the problem wasn’t fixed, go on to the next step.
Failed Condenser or Evaporator Fan Motor
Both of these fans should run when the compressor runs. If the compressor is running and the fans aren't, your fridge will not cool properly.
The condenser fan draws air over the compressor and through the condenser coils. If the fan motor isn't working normally, then the fridge won't cool properly.
- Check the fan blade for physical obstructions. If the blades are cracked, splitting, or missing, replace the blades.
- Rotate the fan by hand. If it doesn't spin freely, replace the motor.
- If it spins freely, test the motor for continuity. Replace the condenser fan motor if the continuity test fails.
The evaporator fan draws air over the cooling coils and circulates this air within the fridge and freezer compartments. If your fridge only has one evaporator fan motor it's located in the freezer compartment. When the fan fails it won't circulate the cold air. In this event, the freezer will start to warm up more slowly, while the refrigerator will warm quickly.
- Check the fan blade for physical obstructions. If the blades are cracked, splitting, or missing, replace the fan blades.
- Note: The fan may not be running if it's iced up due to a freezer building up ice.
- Rotate the fan by hand. If it doesn't spin freely, replace the motor.
- If it spins freely, test the motor for continuity. Replace the evaporator fan motor if the continuity test fails.
- An unusually noisy motor should be replaced as well.
Thermistor Failure (Faulty Defrost Temperature Sensor)
Another problem that prevents your fridge from getting cold enough is a faulty thermistor. The thermistor is a sensor that monitors the air temperature. It is connected to the control board. If the thermistor is defective, the refrigerator does not cool (or may cool continuously).
- Remove the Thermistor.
- There's often one thermistor in the freezer, and one in the fridge.
- Grab a multimeter and continuity test the thermistor. You can measure the thermistor if it is 46 degrees Fahrenheit (7 degrees Celcius) or colder. Place the thermistor tip into a cup of ice water and cool if you're above the target temperature.
- If the value isn't between 10—15kΩ, replace your temperature sensor.
Temperature Control Board Failure
The temperature control board may be another potential cause if the freezer isn’t cold enough. The temperature control board provides the voltage to the fan motors and compressor. Since this is a less common failure, be sure to check other components to be certain this is the cause of the problem.
- If the display LEDs or Temperature Setting button are not responding, it could signal that the board has failed.
- Remove the board from the fridge and reconnect. Verify the wire connections are secure.
- Replace the temperature control board if reconnecting doesn’t solve the problem..
Faulty Compressor Components
Faulty Run Capacitor
Sometimes if the freezer isn't cold enough, the compressor might be having difficulty keeping up. The run capacitor is needed to keep the compressor running on some models. If this capacitor is burned out —and it may smell burnt — the compressor might not be able to run as well as it should.
- Safely remove the capacitor and discharge with a discharge tool.
- On smaller capacitors, you can use a screwdriver to discharge. But be careful as capacitors increase in size.
- Test the run capacitor first with a capacitance meter. If it's faulty, replace it.
Faulty Overload Relay
The overload relay is a protection device in the compressor circuit and is often combined with the start relay. You can find it plugged directly into the side of the compressor. If the fans are running and your compressor won’t start, or if you hear a clicking sound from the unit follow the troubleshooting below.
- Safely remove the start relay assembly.
- Check the overload relay for signs of overheating or arcing.
- This may be a hot module, burnt, or rattles when shaken. Some devices will rattle even if they are good so this isn't a definite test.
- Check for continuity with a multimeter.
- Flip the unit over and test again. If there's no continuity, replace the unit.
Faulty Start Relay
The start relay is a small device mounted to the side of the compressor. It provides power to the run winding, along with the start winding, for a split second at startup to help get the compressor going. If the start relay is defective, the compressor may run intermittently or not at all, and the freezer will not get cold enough. The start relay should be replaced if defective.
- Safely remove the start relay assembly.
- Test Start Relay with a multimeter. View the video above and verify if your start relay is functioning.
- Replace the relay if it fails the testing or has a burnt odor. Depending on your start relay, you may have to test the start capacitor and overload relay first and use a process of elimination. If the other two components pass continuity tests, and your compressor isn't starting, try replacing your start relay.
Compressor Inverter Board Failure
Modern refrigerator compressor technology has shifted from single-phase DC motors to BLDC motors which are electronically commutated.
What this means is that instead of the start relay assembly normally attached to the compressor pins — the start relay, overload relay, and overload capacitor — there is now a sealed inverterboard and a lot of wires. The inverter board modulates the power supplied to the compressor and allows for variable speed and much more efficient operation.
This new technology is harder to test, so follow this helpful video.
The inverter board must be tested by the process of elimination.
- First, test the input voltages. The inverter board will have both a 120V AC main power supply voltage and a 4-6V DC voltage from the main control board. Remember to make all voltage measurements with everything connected.
- If one of these voltages is missing, the inverter board will not work.
- Backtrack to find the issue. You could have a faulty wire harness connector, a bad motherboard, or another issue.
- Second, follow the compressor continuity testing from above to verify your compressor isn't shorted and is okay.
- If the compressor is fine, and the board input voltages are fine, then your inverter board has failed and needs replacing.
The compressor is the workhorse of your fridge. By pressurizing the refrigerant, the compressor ultimately allows the evaporator to remove heat from the air in the freezer. If the compressor is very noisy when you start it up, it may have been damaged in transit, or you could just have a faulty compressor.
If the overload relay, start relay, and start capacitor pass testing, then you may have a defective compressor.
- Test the compressor for continuity by following the video above.
- Resistance values vary based on the compressor.
- Values outside of the range or a short to ground will mean replacing the compressor, which is a costly repair.
- If your fridge is more than a few years old, you may be better off replacing the fridge instead of the compressor.
If there is a refrigerant leak, the freezer won't be able to maintain a proper temperature. Your compressor is likely running non-stop.
- Contact a service technician to inspect your compressor.
- This may result in refilling or replacing your refrigerant, or replacing the entire fridge.
Main Control Board Failure
Finally, if the freezer won’t get cold enough, the main control board might be defective. This is not common. Check the defrost system, cooling fans, and cooling controls first.
- If the buttons on the control board and its LEDs are no longer responsive, remove the board from the fridge, and reconnect.
- Verify the wire connections are secure.
- Replace the control board.