Amana Refrigerator Not Cooling: Troubleshooting Guide... | appliancefaults.com

Technical Background:

MCU logic and voltage paths.

The Amana refrigerator's MCU controls the defrost cycle, fan motor operation, and damper door position based on temperature readings from thermistors. The MCU regulates voltage to components like the defrost heater (120V AC), evaporator fan motor (typically 12V DC), and damper solenoid. A failure in any of these voltage paths or the MCU itself can cause the described cooling issue.

Symptoms:

US homeowner observations.

The freezer is working normally, maintaining a proper freezing temperature (around 0°F). However, the refrigerator compartment is significantly warmer than usual (above 40°F), and food is spoiling. There may be no cooling at all in the fridge section.

Possible Causes:

Faulty Defrost System
Damper Door Issues
Evaporator Fan Motor Failure
Sealed System Problems (Refrigerant Leak or Compressor)
Thermistor Malfunction
MCU (Main Control Unit) Failure

Solution:

1

Unplug the refrigerator and check the evaporator coils in the freezer for ice buildup. If iced, proceed to defrost system check.
2

Check the defrost heater element for continuity using a multimeter. It should show a resistance reading.
3

Test the defrost thermostat for continuity when cold (below 40°F). It should be closed.
4

Inspect the damper door (between freezer and fridge) for proper operation. Make sure it's opening and closing freely.
5

Verify the evaporator fan motor is running. If not, test for 12V DC at the motor terminals.
6

Check the thermistor (temperature sensor) resistance. Compare to a temperature/resistance chart for your model.
7

If all components check out, suspect a sealed system issue. This requires specialized tools and knowledge and is best left to a licensed technician.

Safety Warning:

Always disconnect power to the refrigerator before performing any repairs. Use proper Lock-Out/Tag-Out (LOTO) procedures to prevent accidental re-energizing of the circuit. Some components operate at 120V AC, which can cause serious injury or death.

Prevention:

Regularly clean the condenser coils (located at the back or bottom of the fridge) with a vacuum cleaner brush attachment every 6 months. Avoid overpacking the refrigerator to ensure proper airflow. Ensure the door seals are clean and sealing correctly to prevent warm air from entering. Check temperature settings are appropriate (typically 37F for fridge and 0F for freezer).

Expert Tip:

Amana refrigerators often have a diagnostic mode. Simultaneously press and hold the 'Door Alarm' and 'Temperature Up' buttons for 5 seconds to enter the service mode. This will display error codes and allow you to run diagnostic tests on individual components.

Frequently Asked Questions

•How do I access the defrost heater to test it?

The defrost heater is typically located behind the evaporator coils in the freezer compartment. You may need to remove the back panel of the freezer to access it. Be careful not to damage any refrigerant lines while doing so.

•What resistance reading should I expect from the defrost heater?

The resistance of the defrost heater varies by model, but generally, you should expect a reading between 20 and 50 ohms. An open circuit (infinite resistance) indicates a faulty heater.

•How do I determine the correct thermistor resistance at a specific temperature?

You'll need a temperature/resistance chart specific to your Amana refrigerator model. This information can usually be found in the service manual or online through appliance parts retailers.

Amana Refrigerator Not Cooling: Troubleshooting Guide (Freezer Works)

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the defrost heater to test it?

•What resistance reading should I expect from the defrost heater?

•How do I determine the correct thermistor resistance at a specific temperature?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: