Amana Refrigerator Defrost Heater vs. Defrost Timer... | appliancefaults.com

Technical Background:

Amana refrigerators use a defrost system controlled by either a defrost timer or an electronic control board (MCU). The timer or board periodically activates the defrost heater, melting frost from the evaporator coil. A defrost thermostat protects the evaporator from overheating. The heater is a resistance heating element drawing approximately 5-7 amps at 120V AC.

Symptoms:

US homeowners often report excessive frost buildup in the freezer, preventing proper cooling. Food may spoil quickly. Water may leak inside the refrigerator compartment.

Possible Causes:

Defective defrost timer
Failed defrost heater
Open defrost thermostat
Wiring issues in the defrost circuit
Faulty defrost control board (if equipped)
Blocked defrost drain

Solution:

1

Unplug the refrigerator or turn off the breaker.
2

Locate the defrost timer, typically behind the kick plate or in the control panel. Visually inspect for damage.
3

Use a multimeter to test the defrost heater for continuity. A reading of 20-40 ohms typically indicates a good heater. If open, replace the heater.
4

Check the defrost thermostat for continuity when cold (below 40°F). It should be closed. If open, replace it.
5

If the refrigerator has a defrost control board, inspect it for burned components. If found, replace the board.
6

If the defrost timer is suspected, manually advance it into defrost. Observe if the heater activates. If not, test the timer's contacts using a multimeter for 120V AC output to the heater.
7

Clear any ice blockage from the defrost drain to ensure proper water drainage.

Safety Warning:

Always disconnect power to the refrigerator before performing any repairs. Use Lock-Out Tag-Out (LOTO) procedures to prevent accidental energizing of the circuit. Be aware of high voltage (120V AC) present in the appliance.

Prevention:

Clean the condenser coils every 6 months to improve cooling efficiency and reduce the load on the defrost system. Avoid overpacking the freezer, as this can restrict airflow and increase frost buildup. Regularly check the defrost drain for blockages.

Expert Tip:

Many Amana refrigerators have a service mode accessible by pressing and holding specific buttons on the control panel. Consult the service manual for the exact sequence. The service mode allows you to manually initiate a defrost cycle for testing purposes.

Frequently Asked Questions

•How do I access the defrost timer on my Amana refrigerator?

The defrost timer is typically located behind the kick plate at the bottom front of the refrigerator or inside the control panel at the top. You may need to remove screws or clips to access it.

•What resistance value should I expect from a good defrost heater?

A good defrost heater typically has a resistance between 20 and 40 ohms. However, consult the specific model's service manual for the exact value.

•How often should the defrost cycle occur on my Amana refrigerator?

Typically, the defrost cycle occurs every 8 to 12 hours of compressor run time, lasting for about 20 to 30 minutes. However, some models may have adjustable defrost intervals.

Amana Refrigerator Defrost Heater vs. Defrost Timer Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the defrost timer on my Amana refrigerator?

•What resistance value should I expect from a good defrost heater?

•How often should the defrost cycle occur on my Amana refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: