Short answer first
Jenn-Air documents F3T3 as a possible problem with the hood temperature thermistor or its wiring. The thermistor reports the temperature at the hood, so any automatic response to heat there may not work while the code shows. Use the cooktop below only with the vent fan switched on manually until it is repaired.
Error codes
Reference| Code | Meaning |
|---|---|
| F3T3 | There may be a problem with the Hood Temperature Thermistor or the associated wiring. |
What you observe
- The vent fan runs on by itself — A thermistor reading falsely hot can keep the fan running.
- The code appears during cooktop use — Rising heat and steam are what the hood thermistor sees.
- The vent fan does not respond to heat — Where the unit raises the vent fan when the cooktop gets hot, it may stop doing so.
- NEAR MISS: the vent fan is dead with no code — A fan that never runs, with no thermistor code, is a fan, switch or supply matter.
Likely causes, ranked
- The hood temperature thermistor — Ranked first because F3T3 names the thermistor, and it lives in rising heat and grease vapor every time the cooktop is used, which is hard on a small sensing part.
- Grease on the thermistor or its connector — Cooking vapor leaves a film that can insulate the thermistor or creep into its connector.
- Its connector — A connector that has loosened in the hood heat gives an intermittent or impossible reading.
Diagnostic order, cheapest and safest first
- Run the vent fan manually — Confirm the fan works from its own control; that separates the fan from the thermistor.
- Look at the hood underside — Heavy grease near the vents and filters is worth cleaning before anything else.
- Reset once — With the cooktop cool, reset at the breaker and see whether the code returns.
- Thermistor test — Measuring the thermistor behind the hood panels is technician work.
Reset and owner-safe checks
- Clean the grease filters and hood underside — With the power off and the cooktop cool, remove and wash the filters and wipe the hood underside.
Tools: mild degreaser, soft clothAbout 20 min
- Reset at the breaker — Breaker off for a few minutes, then on.
About 5 min
- Test the fan manually — Run the vent fan at each speed from its own control.
About 3 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.
Safety first
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Let the cooktop and hood cool before cleaning, and switch off at the breaker before reaching around the hood; hood panels hide live wiring. Let the cavity and any surface units cool fully before reaching in or behind them.
When it is a service call
Call for service if F3T3 returns after the filters and hood underside are clean and the unit has been reset, or if the vent fan will not stop. The thermistor sits behind hood panels with live wiring.
Neighboring Jenn-Air oven codes
Generalized information
Generalized information: F3T3 is read here for the Jenn-Air oven line as a whole, which fits Jenn-Air units with a ventilation hood whose code list carries F3T3 as a hood thermistor fault. It is not a reading for ovens without a hood, cavity and probe codes, and models that read F3T3 differently. Model lines can reuse a code with another meaning, so a model-specific page, where one exists, comes first.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
