What causes the F3 code on a Whirlpool microwave?

Key physically stuck or being held down: Object resting against the keypad, or grease holding a button down. Failed membrane switch: A keypad with internal shorts will look like a held key to the control. Humidity sensor out of range (older models): On models where F3 is humidity-related, the sensor itself or its connector is at fault.

Whirlpool · Microwave Moderate

F3 — Key Held Too Long

The control detected a key pressed continuously for over one minute, or a humidity sensor reading outside the valid range on older models. Often a stuck-finger / stuck-button rather than hardware failure.

Keep using it?: Yes, with caution
DIY difficulty: Easy
Verified against: applianceaid.com ↗

How to fix it

Remove anything resting on or against the front panel.
Wipe the keypad with a damp cloth and a little isopropyl alcohol; press each key several times.
Power-cycle at the breaker for 1 minute.
If F3 stays, pull the control panel and reseat the keypad ribbon at the control board.
Replace the membrane switch if the code returns after a clean reseat. On older models that read F3 as humidity-related, replace the humidity sensor.

Why it happens

Typical signs: F3 on the display · Beeping after the keypad is touched · Microwave will not accept any new input

Key physically stuck or being held down Object resting against the keypad, or grease holding a button down.
Failed membrane switch A keypad with internal shorts will look like a held key to the control.
Humidity sensor out of range (older models) On models where F3 is humidity-related, the sensor itself or its connector is at fault.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Whirlpool Microwave Control Panel Membrane Switch (Keypad) Common replacement
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More Whirlpool microwave codes

AccuPop Fail AccuPop Fail — Popcorn Sensor Fault Demo Demo Mode — Not Heating Door Door / Open Door Closed — Safety Reminder F1E4 F1E4 — Appliance Manager or Power Relay Fault F1E5 F1E5 — Inverter Internal Fault F2 F2 — Keypad / Control Fault

All Whirlpool codes → All microwave codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: applianceaid.com.