Whirlpool Microwave F3H — What It Means & How to Fix It
Also shown as F3H1, F4E4, F4 E4 on some models.
F3H, F3H1 and F4E4 point to the humidity sensor or humidity thermistor used for sensor cooking, or its wiring — reset power and call service if the code repeats.
What this code means
Whirlpool attributes F3H and F4E4 to the humidity thermistor and F3H1 to the humidity sensor, each "or the associated wiring". These parts detect steam from food for sensor cycles.
Whirlpool over-the-range microwaves with sensor cooking.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| Humidity sensor or thermistor fault | Common | No — technician job |
| Wiring fault | Occasional | No — technician job |
| Misread | Occasional | Yes — breaker reset |
What you can try yourself
- Reset power for one minute.
- Monitor the display.
- Use a timed cook to verify heating.
- Schedule service if the code returns.
When to call a technician
- Repeat code.
- Sensor cook cycles misbehave.
- Additional F3 codes.
Typical professional repair cost: About $120–$250.
Frequently asked questions
What does F3H mean?
A possible problem with the humidity thermistor or its wiring.
And F3H1?
Whirlpool names the humidity sensor.
What uses the humidity sensor?
Sensor cooking programs, which judge doneness from steam.
Sources checked
- Whirlpool Product Help: F3H - Over-the-Range Microwave
- Whirlpool Product Help: F3H1 - Over-the-Range Microwave
- Whirlpool Product Help: F4E4 - Over-the-Range Microwave
Error meanings can vary by model. This guide was checked against the documentation above; use the manual for the model number on your own appliance when it differs.
Related Whirlpool codes
- Whirlpool Microwave E03 E03 — or a plain F2 — means the keypad reported a problem to the control board; reset power for one minute and call for service if it comes back.
- Whirlpool Microwave SE SE means there is a problem with the keypad (user interface) or its wiring — clean and dry the panel, reset power for a minute, and call service if SE remains.
- Whirlpool Microwave E11 E11 and E12 point to the microwave's gas sensor — the sensor used for automatic cooking — or its wiring; reset power for a minute, and expect to need a technician if it returns.
- Whirlpool Microwave E13 E13 means the oven did not pre-heat correctly, with a possible problem in the appliance control board or its wiring; reset power for a minute and call service if it repeats.
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