JennAir JMV Code F3H: humidity thermistor

What F3H means

Owners of JennAir over-the-range microwave hoods such as the JMV9196CS or a JMV8000 series model may see F3H, which says there may be a problem with the humidity thermistor or its wiring. That sensor lets the sensor-cook modes judge steam from the food. The usual result is that automatic sensor cooking stops working while manual cooking keeps going. Built-in JennAir microwaves name a humidity sensor instead.

Common causes of F3H

Humidity thermistor has failed or drifted
Wire or connector to the thermistor is loose
Steam or grease has coated the sensor area

✓ One safe check you can try

1. Press Stop/Cancel and open the door to let steam clear. 2. Wipe the cavity walls and the door seal when cool. 3. Use manual time and power instead of sensor settings. 4. Close the door and test once. 5. If F3H stays visible, book a visit.

! Why to stop there

The sensor connects to the control through a wiring harness inside the housing.
Sensor-cook behavior depends on a good humidity reading, so a half-working sensor spoils results.
Opening the hood means working beside high-voltage parts.
We state our price in writing before starting and back the work for 30 days.

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

F8 E3JennAir Built-In Microwave Code F8 E3: one more cooling alert Sabbath, Sab, 5Ab, or 5A6JennAir Built-In Microwave Message "Sabbath, Sab, 5Ab, or 5A6": Sabbath Mode On F8 E4JennAir Built-In Microwave Code F8 E4: exhaust air sensor SEJennAir JMV Code SE: keypad problem F8E5JennAir JMV Code F8E5: exhaust air temperature sensor F9JennAir JMV Code F9: appliance or relay control board F9Q1JennAir JMV Code F9Q1: touch pad problem FC E1JennAir OTR Microwave Code FC E1: router connection timed out

F3HF3H questions

Will F3H stop all my cooking?

Usually not. Manual time and power should still work because they do not need humidity readings. The sensor-based programs are the ones that give up.

Does steam from a pot on the range cause F3H?

Heavy steam from below can reach the hood sensor area, but the code means the sensor circuit has a problem, not just humid air. If F3H appears often, the sensor needs checking.

Does F3H mean the same thing as F3H1?

They are close cousins. F3H names the humidity thermistor, while F3H1 names a humidity sensor. We treat both as a sensor circuit job and test the part itself.