Refigerator not cooling and frost build up on coil infront of defrost thermostat

Refrigerator & Freezer Repair
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Brand: Maytag
Model Number: MF12269VEM10
Main Symptom:Not cooling
What happens & when: Ice build up on coil in front of the defrost thermostat

Error Code (if any):
Parts or tests already tried: Compressor. Defrost thermostat, Thermister, control board
Photos / video link:

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For your Maytag MFI2269VEM10, part ( Whirlpool WPW10166768 Refrigerator Heating Element | Genuine OEM Part ) is the defrost heater assembly mounted on the evaporator coil in the freezer section. Its job is to melt frost off the evaporator during the automatic defrost cycle. If it fails, the evaporator coils ice over, causing poor cooling and restricted airflow.

Symptoms of a bad WPW10166768

  • Heavy frost or solid ice buildup on the evaporator cover

  • Refrigerator section warming up while freezer may still seem cold

  • Evaporator fan hitting ice

  • Unit runs continuously

  • Defrost system failure symptoms

How to Test WPW10166768

1. Unplug the refrigerator.

Safety first.

2. Access the evaporator.

  • Remove freezer drawer and baskets.

  • Remove the rear freezer panel.

  • The evaporator coil and heater will be visible.

3. Disconnect the heater.

Unplug the heater connector so you’re testing only the heater.

4. Check continuity with a multimeter.

  • Set meter to Ohms (Ω) or continuity.

  • Touch one probe to each heater terminal.

Expected result:

  • Continuity present (typically several dozen ohms) = heater likely good.

  • OL / infinite resistance / no continuity = heater is bad and must be replaced.

Additional Check

If the heater tests good, also test:

  • Defrost thermostat (bi-metal)

  • Defrost thermistor

  • Main control board defrost circuit

These components can cause the same frost buildup symptoms.

How to Replace WPW10166768

  1. Unplug refrigerator.

  2. Remove freezer drawer and baskets.

  3. Remove evaporator cover.

  4. Defrost any heavy ice with a steamer or hair dryer (avoid overheating plastic).

  5. Disconnect the heater wiring harness.

  6. Release heater clips from the evaporator.

  7. Install the new WPW10166768 in the same position.

  8. Reconnect wiring.

  9. Reinstall evaporator cover, baskets, and drawer.

  10. Restore power and verify operation.

Quick Diagnosis Tip

Before replacing the heater, measure resistance:

  • No continuity = replace WPW10166768.

  • Continuity present = investigate the defrost thermostat/thermistor and control board before ordering parts.