Written by
Tessa Brandt Appliance Care EditorPublished October 29, 2026
VERIFIED
Error codeE21
ApplianceMicrowave
E21 in plain terms
An open circuit in the thermal sensor is what E21 reports on a Maytag over-the-range microwave. The control board noticed it. Suspects on Maytag’s list are the sensor, the board itself, and the leads that join them.
Reset before anything else
Turn the breaker off, count off one minute, then turn it on. Stay near the microwave for another minute to confirm E21 does not come back, and finish by checking that it runs.
A code that sticks around
If E21 persists, it is time for a technician to inspect the sensor circuit rather than keep cycling the power.
Related codes
E22: same circuit, but reading shorted instead of open.
E23: heater, control board or wiring, tied to pre-heat.
E24: overheat, with the thermal and gas sensors both on the list.
Book microwave repair in the Bay Area
Phone (415) 649-2156 to line up a technician for your Maytag microwave anywhere around San Francisco, or read about Maytag microwave repair first. Mention E21, the model number and the reset you ran.
Model compatibility: Maytag reuses codes across series and model years, so E21 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
The thermal sensor circuit reported open to the control board.
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your Maytag appliance?
Book a specialist visit for a clear estimate and approval before any repair.
You submit a request with your appliance model and symptom, we confirm an appointment window, and a technician performs an on-site diagnosis. You then receive a clear estimate and decide whether to proceed before any repair begins.
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Replacement parts are selected for the exact model and confirmed with you before ordering or installation.
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Ready to get your Maytag appliance working again?
Book a repair online or call us — clear estimates and approval before any repair work begins.
