KitchenAid Over-the-Range Microwave Code F3H1: humidity sensor alert

What F3H1 means

KitchenAid over-the-range microwave hood combinations like the KMHS120ESS, KMHC319ESS and KMLS311HSS display F3H1 when there may be a problem with the humidity sensor or its wiring. The sensor tells the oven how much steam the food produces. Without a good reading, auto-sensing programs can stop with the code displayed.

Common causes of F3H1

Humidity sensor not responding
Sensor connector loose
Grease or moisture on the sensor

✓ One safe check you can try

1. Cancel the program. 2. Wipe the cavity and the door seal dry. 3. Leave the door open for ten minutes. 4. Break power briefly, about a minute, and reconnect. 5. Run a timed cycle. If F3H1 appears again, call us.

! Why to stop there

The sensor is deep in the airflow path and not an easy home job
We test the part and the wiring before replacing it
You see a written price first and get 30 days of warranty

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Microwave codes

Probe or Insert ProbeKitchenAid Combination Microwave Message "Probe" or "Insert Probe": Seat the meat probe in its jack PUSH or PSHKitchenAid Built-In Microwave Message PUSH or PSH: The oven is waiting for Start Registration ErrorKitchenAid Over-the-Range Microwave Message "Registration Error": Check the home network and try again Sabbath, Sab, 5Ab, or 5A6KitchenAid Built-In Microwave Display Sabbath, Sab, 5Ab or 5A6: Sabbath Mode is on SEKitchenAid Over-the-Range Microwave Code SE: Keypad or user interface problem F4 E4KitchenAid Combination Microwave Code F4 E4: Humidity sensor signal missing from the cavity F7 E9KitchenAid Over-the-Range Microwave Code F7 E9: Is the upper vent door blocked? Flashing Time, Clock, 12:00, Power Loss or Enter TimeKitchenAid Built-In Microwave Messages Time, 12:00 and Power Loss: Set the clock after an outage

F3H1F3H1 questions

Can a steamy kitchen cause F3H1?

Temporarily it might upset the sensor, but a code that persists after drying means the part or wiring needs service.

Which programs are blocked?

Sensor cooking, reheating and popcorn style programs that rely on steam detection may not work.

Is this a safety risk?

Not directly. It is a convenience feature, but we still recommend a check so the problem does not grow.