Microwave shows E18 and the cooling fan runs continuously even when not cooking.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Stuck relay on control board, Faulty temperature sensor reading high, Shorted wiring to fan relay, Control board logic fault

Safety first: Turn off power at the breaker before extended troubleshooting.

Initial steps:

Allow the unit to cool for 30–60 minutes with power off.
Restore power and observe whether the fan starts immediately without a cook command.

If fan runs continuously and E18 remains:

The control board relay or temperature sensor is likely faulty.
These components are not user-serviceable; schedule service for diagnosis and replacement.

Hard 4/5

Main Control Board

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