Two descriptions of F21 exist in KitchenAid's help pages. Both end with the same one-minute breaker reset.
Model compatibility: KitchenAid reuses codes across series and model years, so F21 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
What this code means
KitchenAid lists F21 as a problem with power supply frequency, and elsewhere as cooktop overheating with installation to verify and about 5 minutes to cool.
Summary of the two readings
| Where | What is stated |
|---|---|
| Electric cooktop article | A frequency issue in the power supply |
| Two radiant, electric articles | The cooktop could be overheating: check the installation and allow around 5 minutes to cool |
That is a two-to-one split, and the articles never say which wording matches which cooktop. For that reason both appear here.
At a glance
| Code | F21 |
|---|---|
| What it means | Either a power supply frequency problem or cooktop overheating, depending on which description applies. |
| What you can check | Allow about five minutes of cooling and verify the installation. Then turn the breaker or breakers off for a minute, back on, and watch for a minute to confirm the code stays off. |
| When to call a technician | If F21 comes back after cooling and the reset, request service and mention which description seemed to fit your cooktop. Have the model number ready. |
Questions people ask
Which meaning is right for my model?
KitchenAid does not pair meanings with models.
What does checking the installation mean?
No checklist is given. For airflow points tied to another overheating code, see the C81 / C83 page.
Steps, whichever reading applies
- Allow roughly five minutes of cooling and verify the installation, in case overheating is the explanation.
- Remove power at the breaker or breakers for a minute, then put it back.
- Monitor for one minute; F21 should stay off the display.
- Confirm that the cooktop works.
The final lines of the frequency article mention the oven, but the procedure does not change.
Codes worth comparing
- F25: trouble with the supply to the cooktop; an electrician is named for repeats.
- F61 / F63 / F64: a family covering control, power module, wiring and supply.
KitchenAid cooktop service in five metro areas
Service is offered in the Miami, New York, Houston, Los Angeles and San Diego metro areas. If F21 comes back after cooling and the reset, ring (844) 919-2035 and keep the model number handy, plus a note of which description seemed to fit.
Source: KitchenAid Product Help, Electric Cooktop: Error Code or Indicator Light
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.
Sources & references
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