Whirlpool Refrigerator: Evaporator Fan Blade Hitting... | appliancefaults.com

Technical Background:

The Whirlpool refrigerator uses a defrost cycle to melt frost buildup on the evaporator coil. The defrost cycle is typically controlled by a defrost timer or a defrost control board (MCU), which activates the defrost heater. The defrost thermostat acts as a safety switch, preventing the heater from overheating. The evaporator fan circulates cold air throughout the refrigerator and freezer compartments.

Symptoms:

US homeowner observes excessive frost buildup on the evaporator coil, causing the evaporator fan blade to make noise or stop spinning entirely. The freezer temperature may fluctuate, and the refrigerator may not cool properly.

Possible Causes:

Defrost heater malfunction
Defrost thermostat failure
Defrost timer malfunction (on older models)
Damaged or warped evaporator fan blade
Air leaks into the refrigerator compartment
Faulty defrost control board

Solution:

1

Unplug the refrigerator from the 120V AC outlet.
2

Locate the evaporator cover inside the freezer compartment. It's typically a plastic panel at the back of the freezer.
3

Remove the evaporator cover using a 1/4-inch nut driver to access the evaporator fan and coil.
4

Inspect the defrost heater for continuity using a multimeter. A reading of OL (open line) indicates a faulty heater and it should be replaced.
5

Test the defrost thermostat for continuity while the coil is frosted. It should show continuity (closed circuit) when cold (below 40°F) and open when warm. If it's open when cold, replace it.
6

Check the defrost timer (if applicable) or defrost control board for proper operation based on the wiring diagram. Use a multimeter to verify proper voltage (typically 120V AC) is reaching the components.
7

If the fan blade is damaged, replace it. Ensure the new fan blade is properly seated on the motor shaft. Also, check the fan motor for proper operation. A locked rotor or unusual noise indicates motor failure. Replace the fan motor if needed.

Safety Warning:

Disconnect power (LOTO - Lock Out Tag Out) to the refrigerator before performing any repairs. Capacitors in the control board can hold a dangerous charge even after the refrigerator is unplugged. Use extreme caution when working with electrical components. Some components might operate at 120V AC.

Prevention:

Regularly inspect the door seals for damage and replace if necessary to prevent air leaks. Avoid overpacking the refrigerator, as this can restrict airflow and contribute to frost buildup. Clean the condenser coils at least twice a year to ensure efficient cooling. This can be done with a vacuum cleaner and a brush attachment.

Expert Tip:

Many Whirlpool refrigerators have a service mode that allows you to manually initiate a defrost cycle. Consult the technical sheet behind the refrigerator to find the exact sequence for your model. This is useful for testing the defrost components.

Frequently Asked Questions

•How do I test the defrost heater?

Unplug the refrigerator and locate the defrost heater behind the evaporator coil. Use a multimeter set to ohms to check for continuity across the heater terminals. A reading of OL (open line) indicates a faulty heater.

•What if the defrost thermostat is covered in ice?

If the defrost thermostat is encased in ice, it's difficult to get an accurate reading. Use a hairdryer on low setting to gently melt the ice surrounding the thermostat before testing. Remember, it should show continuity (closed circuit) when cold.

•Where can I find the wiring diagram for my Whirlpool refrigerator?

The wiring diagram is usually located behind the refrigerator, often taped to the back panel or inside a compartment near the compressor. It provides valuable information for troubleshooting electrical components.

Whirlpool Refrigerator: Evaporator Fan Blade Hitting Frost - Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the defrost heater?

•What if the defrost thermostat is covered in ice?

•Where can I find the wiring diagram for my Whirlpool refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: