Amana Refrigerator Evaporator Fan Ice Buildup Noise:... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) manages the defrost cycle. The defrost cycle melts frost buildup on the evaporator coil. This involves activating a defrost heater. The evaporator fan circulates cold air throughout the refrigerator. If the defrost system malfunctions, ice accumulates, eventually interfering with the fan blades. Voltage to the fan motor is typically 12V DC or 120V AC depending on the model.

Symptoms:

The homeowner hears a loud buzzing or scraping noise coming from the freezer compartment. This is often intermittent, worsening over time, and may be accompanied by reduced cooling performance in both the freezer and refrigerator sections. Ice may be visible on the back panel inside the freezer.

Possible Causes:

Defective defrost heater
Faulty defrost thermostat
Failed defrost timer or control board
Damaged evaporator fan motor
Air leaks into the refrigerator compartment
Door seals not sealing properly

Solution:

1

Unplug the refrigerator from the 120V AC outlet.
2

Remove the evaporator cover inside the freezer compartment using a 1/4-inch nut driver.
3

Inspect the evaporator coil for excessive ice buildup.
4

Check the defrost heater element for continuity using a multimeter. A reading of OL indicates a failed heater.
5

Test the defrost thermostat for continuity when cold (below 40°F). It should show continuity. Replace if open.
6

If the heater and thermostat are good, inspect the defrost timer or control board. Some models have a test cycle you can initiate. Consult the service manual.
7

Manually defrost the evaporator coil with a hair dryer (carefully!). Reassemble the components after melting the ice.

Safety Warning:

Always disconnect power to the appliance before performing any repairs. Lock Out Tag Out (LOTO) procedures should be followed. Some components operate at 120V AC, which can cause serious injury or death.

Prevention:

Regularly inspect and clean the door seals to ensure a tight seal. Avoid leaving the refrigerator door open for extended periods. Consider manually defrosting the refrigerator every 6-12 months to prevent excessive ice buildup.

Expert Tip:

Some Amana refrigerators have a forced defrost cycle that can be initiated by pressing and holding specific buttons on the control panel. Consult the service manual for the correct sequence for your model.

Frequently Asked Questions

•How do I test the defrost heater?

Disconnect the heater from the wiring harness. Using a multimeter set to ohms, measure the resistance across the heater terminals. A reading close to zero or OL (open loop) indicates a faulty heater. A typical resistance value is between 20 and 50 ohms, but refer to the service manual for the exact value.

•Where is the defrost thermostat located?

The defrost thermostat is typically clipped to the evaporator coil, usually near the top. It is a small, round or rectangular component with two wires attached. It's designed to open and close based on the coil temperature.

•How can I tell if the control board is faulty?

Diagnosing a control board issue requires more advanced troubleshooting. First, ensure all other components (heater, thermostat, fan motor) are functioning correctly. If those components are good, and the refrigerator is still not defrosting or the fan isn't running, the control board is likely the culprit. Replacing the control board is often the best course of action in these cases. Consult the service manual for specific diagnostic procedures.

Amana Refrigerator Evaporator Fan Ice Buildup Noise: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the defrost heater?

•Where is the defrost thermostat located?

•How can I tell if the control board is faulty?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: