Refrigerator ice or frost buildup?

A burned-out defrost heater cannot melt frost from the evaporator coil during defrost cycles, allowing heavy ice to accumulate.

Likely causes · most likely first

Defrost Heater

Moderate DIY Part: $20–$50
Evaporator Assembly

Moderate DIY Part: $80–$200

When defrost fails, the evaporator becomes encased in ice that blocks airflow and further prevents effective defrosting.
Electronic Control Board

Moderate DIY Part: $80–$180

A faulty control board may not initiate defrost cycles at correct intervals, allowing unchecked frost accumulation on the evaporator.
Thermistor (Temperature Sensor)

Moderate DIY Part: $15–$40

An inaccurate thermistor can cause the defrost cycle to end prematurely before all frost is cleared from the evaporator.

See the faulty part in 3D.

Tap a highlighted part to see exactly why it fails, how to verify it's the problem, and how to replace it.