The short answer
1d21 is how this oven reports a problem in the temperature sensor circuit. The code table records the documented meaning, and the causes below it are ordered by how often each one is the answer. Keep using it only while the results are acceptable.
The documented code and its meaning
Reference| Code | Meaning |
|---|---|
| 1d21 | There may be a problem with the Oven Temperature Sensor, the Control, or the associated wiring. |
What you actually observe
- Results are uneven from one use to the next — An intermittent reading gives an intermittent result.
- The fault followed a period of heavy or unusually long use — Thermal cycling is what ages both the element and its plug.
- The oven takes far longer than it used to — A control that cannot trust its reading waits rather than stops.
- NEAR MISS — no heat at all, ever — That is a heating-circuit or supply question and it belongs elsewhere.
Causes, most likely first on this oven
- The sensor element itself drifting out of range or going open — These elements wander rather than break, so results go off well before the control refuses the reading outright.
- Corrosion or slackness at the sensor plug — That plug lives in the hottest, dampest part of the run, which is why it — and not the element — is so often what has failed.
- Chafed sensor wiring where it passes through the cavity wall — The grommet at the wall is where the insulation wears, and a conductor touching metal reads as a short to the control.
- The board input that reads the sensor — Rare in practice: the reading circuit on the board sees out both the element and its wiring.
Check in this order, and why
- Note whether the fault appears cold or only once the unit is hot — Whether it faults from cold or only when hot decides which half of the circuit to look at first.
- Get the sensor resistance read at the plug — One resistance reading at the plug separates element, wiring and board in a single measurement.
- Have the plug at the sensor examined for corrosion and heat damage — It is the cheapest repair in this family and the most frequently found.
- Keep the board as the last suspect — Board last: everything ahead of it is both likelier and cheaper.
What an owner can safely check
- Drop the breaker for a minute and bring it back — Sometimes a stored fault goes for good; an immediate return means it is live.
About 3 min
- Note the temperature behaviour you have seen recently — Food cooking unevenly or a long pre-heat in the weeks before the code is the useful history here.
Tools: pen and paperAbout 5 min
- Stop before the cavity wall or the rear cover is disturbed — The sensor run is not an owner-serviceable path, and the checks stop at the cavity wall.
Before anything is opened
Safety
Before any panel comes off, unplug the appliance or switch off its breaker: a capacitor can hold a charge after the power is off. Built-in ovens rarely have a plug; the breaker is what isolates them. Cavity and door glass hold heat long after the cycle has finished. Leave the door switch and the latch wiring exactly as the factory set them: they cut power where the design intends, and that is not a wire to move.
When this stops being an owner job
Arrange a visit as soon as the code repeats after a power-down. Past there the work needs a meter or a panel removed, and a wall oven has to be unseated from its cabinet before the rear connections are reachable. Call sooner than that if you smell burning, see scorching around the control area, or the appliance trips the breaker when it starts — any one of those is a stop-now signal rather than a wait-and-see one.
Nearest error-code pages
What this page does not cover
Treat this as the family-agnostic reading of 1d21 for Maytag oven models on the common control platform. Older control generations that reuse the same characters are not covered, and neither is anything family-specific: wiring colours, connector pin numbers, torque figures and part numbers all change from family to family and are deliberately absent. A family or model page, where one exists, is the more specific answer and should be read in preference to this one — the linked code index collects them.
Other Maytag oven codes
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