Written by
Maren Coleman Appliance Care EditorPublished October 29, 2026
VERIFIED
Error codeF21
ApplianceCooktop
Which F21 do you have?
Whirlpool Product Help gives this code two descriptions, and which one fits depends on the cooktop.
Electric cooktops: the frequency of the incoming power supply is the issue.
Radiant models and electric-plus-induction models: the cooktop may be overheating.
For the overheating reading
Confirm the installation is correct, then give the cooktop about 5 minutes to cool down.
The reset that applies to both
Flip the breaker to off and leave it there for a minute.
Flip it on.
See if F21 shows up once more.
See also
F2: an area of the cooking surface has become too hot.
F25: trouble with the electrical feed to the cooktop.
F21 service in San Francisco
If F21 is still showing after the cooling time and a reset, book a visit with Whirlpool cooktop repair. Call (415) 687-4102 and have your model number and the steps you took ready for the technician.
Model compatibility: Whirlpool 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.
Plain language
What this code means
F21 indicates a power supply frequency problem on electric cooktops, or possible overheating on radiant and induction models.
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 Whirlpool appliance?
Book a specialist visit for a clear estimate and approval before any repair.
Repair for the Whirlpool WCI55US0JS 30-inch induction cooktop in San Francisco: zones that stay cold, pan detection problems, overheat shutdowns and dead…
F36 and F37 share one help entry: a possible induction coil temperature sensor problem. On radiant element cooktops, F36 refers to touch control communication.
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.
Yes. We provide an upfront estimate after diagnosis. No parts are ordered or installed until you approve the work, so there are no surprise charges.
Replacement parts are selected for the exact model and confirmed with you before ordering or installation.
Service areas are listed on the Locations page. Contact us with your ZIP code to confirm current coverage for your address.
Ready to get your Whirlpool appliance working again?
Book a repair online or call us — clear estimates and approval before any repair work begins.
