Tubular sheathed heating element of the type used in ovens

Generic photo: RayFrancoPhD · CC BY-SA 4.0

How to test a refrigerator defrost heater

The defrost heater (glass tube, metal sheath or foil type) melts frost off the evaporator a few times a day. A good heater reads in the low tens of ohms; use the wattage math to check the exact value.

Cross-checked ~45 min moderateBrands: All

Before you start

Unplug the appliance or turn off the breaker before opening panels or disconnecting parts
Take a photo of the wiring before removing any wire
Resistance and continuity tests are done with power OFF and the part isolated
Do not chip ice with tools near the evaporator: a punctured tube is a sealed-system repair (EPA 608 technician only)
Let a glass-tube heater cool before touching it

Diagnostic steps

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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