Whirlpool Microwave Error Code 1d21: Meaning and Fix
Reading the microwave display
On a microwave the code replaces the clock on the display. Unplug the unit for a minute to see if it clears, and note the code before you do. Whirlpool-family codes are usually read as a letter and number pair, with an E sub-code after it.
Whirlpool is the parent platform for Maytag, KitchenAid and Amana, so many of its control boards and fault codes reappear across those brands. Its panels typically report two-part codes such as F5 E2 or flash sequences on the keypad. The codes apply to model numbers such as GU980SCGB2, GU980SCGQ2 and GEW9200LW0; check the label on your unit to confirm yours.
What causes 1d21
- Sensor has drifted, opened or shorted out
- Thermal fuse or high-limit device has tripped
- Sensor harness is loose, pinched or corroded at the connector
- Airflow restriction made the appliance run hotter than it should
- Control board is misreading the sensor signal
How to fix it
- Cycle the power: unplug the microwave (or switch off its breaker) for one minute, restore power and test it briefly with a cup of water.
- Before opening any panel, switch off the breaker or unplug the appliance; this circuit can carry line voltage.
- Power the unit down and let it cool, then clear any vent, filter or airflow restriction before re-testing.
- Locate the sensor named in the code and check that it is seated, undamaged and connected.
- With the connector unplugged, measure the sensor resistance with a multimeter and compare it to the chart for the model; an open or shorted reading means the sensor is bad.
- Replace the sensor (or thermal fuse) if it fails the test, then run a short cycle to confirm the code stays away.
- Run a full short cycle or function again and confirm the code stays gone before putting the appliance back into normal use.
Parts you may need
| Part | Part no. | Buy |
|---|---|---|
| Fuse Thrml | W11707984 | Find part |
Part numbers are OEM references; confirm fit by your model number before ordering. Some links are affiliate links; we may earn a commission at no extra cost to you.
Questions
What does 1d21 mean on a Whirlpool microwave?
It is a fault code from the Whirlpool control. It indicates a problem with a temperature sensor. A power reset is the first thing to try.
Can I keep using the microwave while it shows 1d21?
You can try it after a power reset. If the code returns, the affected function may not run properly, so it is worth fixing soon before it causes a bigger failure.
Do I need a technician to clear 1d21?
Many owners can fix it themselves. Start with the reset and the inspection steps, and only call a technician if the part tests bad and you do not want to replace it.
Other Whirlpool microwave codes
Sources
Part numbers are OEM references; confirm fit by your model number before ordering. Meanings compiled from manufacturer and parts-retailer documentation; see sources below. Unplug the appliance before opening it.
Applies to models including GH5184XPS4, MH1150XMQ0, MH7140XFQ0, MH7140XFB0, MH7140XFQ1, MH7140XFB1, MH1150XMS1, MH1150XMB0.