What the code means
Jenn-Air documents F3C as a possible problem with the cavity temperature thermistor or its wiring. The thermistor reports how hot the cooking cavity is, so the control cannot regulate heat while it reads wrong. Do not use the cavity until the code is cleared and stays clear.
Error codes
Reference| Code | Meaning |
|---|---|
| F3C | There may be a problem with the Cavity Temperature Thermistor or the associated wiring. |
What the oven does alongside the code
- The code shows only once the cavity is hot — Heat-related connection faults appear late and clear as the unit cools.
- Preheat behaves oddly — Preheat ends early, or runs on, when the reading is off.
- Temperatures run wrong before the code — A thermistor drifting out of range can make results run hot or cold first.
- NEAR MISS: a code naming the oven temperature sensor — Some Jenn-Air codes name an oven temperature sensor instead; that is a different part with its own checks.
Causes, most likely first
- The cavity temperature thermistor — Ranked first when F3C is steady and returns after every reset: a thermistor that has failed gives the same bad reading each time, and it is the part the meaning names.
- Its connector — The thermistor plugs into the harness near the cavity wall, where heat cycling loosens and darkens terminals.
- Wiring along the cavity — Leads routed close to the cavity harden with heat and can crack where they bend.
What to check first, and why
- Reset and watch the timing — Note whether the code returns at once or only once the cavity is hot.
- Look inside the cavity — With it cool, check for anything displaced near the cavity walls, such as a loose shield or foil.
- Watch the first preheat — If the unit heats at all, an oven thermometer shows whether it regulates far off its setting.
Reset and owner-safe checks
- Reset at the breaker — Breaker off for a few minutes, then on.
About 5 min
- Clear the cavity — Remove foil, liners and cookware that crowd the walls, and check nothing has come loose inside.
About 3 min
- Check with an oven thermometer — If the cavity still heats, compare a thermometer reading with the setting once it has settled.
Tools: oven-safe thermometerAbout 30 min
- Stop here if the next check needs a meter — Testing a part or its wiring means live terminals or disassembly, which is technician work.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. The thermistor sits against a cavity that stays hot long after cooking, and on built-in units reaching it means removing the unit; leave that to a technician. If the range or oven has to come forward, use two people: it is heavy, and a range is held by an anti-tip bracket that must be re-engaged when it goes back.
Reset or service call?
Call for service when F3C returns after a reset with the cavity clear, or if the cavity runs far hotter than its setting. The thermistor and its harness sit behind cavity panels, and testing them needs a meter and the model's specification.
Neighboring Jenn-Air oven codes
Scope of this code reading
Scope: the documented meaning of F3C for Jenn-Air units whose code list carries F3C as a cavity temperature thermistor fault. Out of scope: oven temperature sensor codes, meat-probe codes, and models that read F3C differently; so is model-level detail such as connector positions and part numbers. A model-specific page, where one exists, is the more precise source.
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