Microwave runs but not heating: what to check (and what not to)

If a microwave runs but doesn’t heat, the issue can be simple (door switch) or high-voltage (magnetron/capacitor).

Safety warning

Microwaves contain high-voltage components that can retain charge even unplugged. Do not open the cabinet unless you’re trained.

1) Try a different outlet and reset power

Unplug for 60 seconds, then retry.

2) Check the door latches and switches (from the outside)

If the door doesn’t fully close/align, some models will “run” but not energize the magnetron.

3) Confirm settings

Make sure it’s not in a “timer” or low-power mode.

4) When to repair vs replace

If it’s a built-in or high-end unit, a service call can make sense. For cheap countertop models, replacement is often the move.

Helpful replacement shopping