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Error code reference

Maytag Range Error Code 1d21

Runaway temperature (950°F) with door locked

Maytag codesMaytag range codes

Runaway temperature (950°F) with door locked – sensor resistance greater than 2787 ohms; completely disables oven (requires power-on reset).

First step from the service manual

Check oven temperature sensor and wiring; BAKE flashes on display.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
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What 1d21 means on a Maytag range

Error code 1d21 on a Maytag range signals that the control board detected a runaway temperature condition in the upper or single oven cavity, with the door lock engaged. Specifically, the oven reached or exceeded 950°F, well above any normal baking or broiling operation, while the door latch was active. This typically points to a failure in the oven temperature sensor (RTD sensor) sending incorrect resistance readings, or to relay contacts on the control board that have welded shut, leaving the bake or broil element energized without the board's command. Both scenarios allow heat to climb unchecked.

For homeowners, this means your oven's safety monitoring system caught the cavity getting dangerously hot and shut things down. The door may have locked during a self-clean cycle, or the lock engaged as a response to the high-heat event. Either way, the range is protecting itself, and you, from an uncontrolled heating situation that could damage the oven or create a fire hazard.

Clearing the code starts with disconnecting power to reset the control board. After power is restored, the sensor and relay contacts need to be inspected before the oven is used again. Simply resetting without diagnosis risks the condition recurring.

Source: manufacturer service documentation.

Common causes of 1d21

  1. 01

    Welded or stuck relay contacts on the control board

    Part replacement

    If the bake or broil relay contacts on the control board weld closed, the element stays energized continuously regardless of the board's commands, driving the oven temperature past 950°F. This is a leading cause of runaway temperature faults and requires control board replacement.

  2. 02

    Faulty oven temperature sensor (RTD sensor)

    Part replacement

    A failed RTD sensor can send a resistance reading to the control board that is far lower than the actual oven temperature, causing the board to continue calling for heat well past safe limits. Resistance should measure approximately 1080 ohms at room temperature; readings outside normal range confirm sensor failure.

  3. 03

    Damaged or shorted oven sensor wiring harness

    Part replacement

    If the wiring between the temperature sensor and the control board is shorted or has degraded insulation, common near the oven cavity where heat exposure is high, the board receives inaccurate temperature data and may allow overheating before triggering the 1d21 fault.

  4. 04

    Door lock mechanism failure during self-clean cycle

    Part replacement

    The 1d21 code is tied specifically to a locked-door condition, meaning a self-clean cycle is the most common context. If the door lock motor or latch assembly malfunctions and the oven simultaneously runs too hot, the locked state combined with the temperature fault produces this code. The lock assembly itself may need replacement if it fails to release after the fault clears.

See the test procedure for each cause

Frequently asked questions about 1d21

What does error code 1d21 mean on a Maytag range?
Code 1d21 means the control board detected a runaway temperature of 950°F or higher in the upper or single oven cavity while the door was locked. This is a safety fault designed to stop an uncontrolled heating event. It most commonly occurs during or after a self-clean cycle, where both high heat and the door lock are active simultaneously.
Is it safe to use my Maytag range with a 1d21 error code active?
No, you should not use the oven until the cause of the 1d21 code has been diagnosed and resolved. A runaway temperature condition at 950°F indicates either a stuck relay keeping the heating element on or a sensor feeding bad data to the control board. Both of which can cause the oven to overheat again. Disconnect power, allow the oven to cool completely, and inspect the sensor and relay contacts before resuming use.
How do I fix error code 1d21 on a Maytag range?
Start by disconnecting power to the range for at least 5 minutes to reset the control board. Once power is restored, check the oven temperature sensor resistance. It should read around 1080 ohms at room temperature using a multimeter. If the sensor reads open, shorted, or significantly out of range, replace it. If the sensor tests good, inspect the control board for relay contacts that have welded shut; a board with stuck relays requires replacement. Also examine the sensor wiring harness for heat damage or shorts near the oven cavity.
How much does it cost to fix a 1d21 error code on a Maytag range?
Repair cost depends on the failed component. An oven temperature sensor (RTD) typically costs $20 to $60 for the part, and replacing it is a manageable DIY repair requiring only a screwdriver. A control board replacement is more expensive, ranging from $150 to $350 for the part depending on the model, with professional labor adding $100 to $200. Diagnose the sensor first since it is the simpler and cheaper fix; if the board relays are the problem, weigh repair cost against the age of the appliance.
Why did my Maytag oven show code 1d21 after a self-clean cycle?
Self-clean cycles run at extreme temperatures, typically between 800°F and 900°F, which pushes components close to their limits. The 1d21 code appears when the oven exceeds 950°F during this process, which can happen if the temperature sensor has drifted and is reading low (causing the board to add more heat than needed), or if relay contacts on the control board have welded shut from repeated high-heat cycling. The door-locked condition referenced in this code is consistent with the self-clean door latch being engaged. After the oven cools and power is reset, test the sensor before running another self-clean cycle.

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