Error code · Microwave

Whirlpool Built-In Microwave with F4: Oven Cavity Control

Medium · inspection needed

Code: F4
Appliance: Microwave
Brand: Whirlpool
Warranty: 30-day workmanship

What F4 means

A plain F4 on a Whirlpool built-in microwave or microwave drawer, such as WMC50522AS, points to the oven cavity control or the wiring attached to it. The display shows F4 instead of a normal readout. When F4 is followed by E and a digit, the code points to a more specific part, such as the inverter or a sensor, and has its own explanation. For plain F4, the brand gives a power reset and names no failed part.

Common causes of F4

Oven cavity control board
Wiring and connectors serving that control
Connections between the cavity control and the main control

✓ One safe check you can try

1. Turn the microwave's breaker off and wait a full minute. 2. Turn it back on. 3. See whether F4 comes back within the next minute. 4. If it does not, a brief normal cycle confirms the oven works. 5. If F4 does return, keep the microwave off until we check the control.

! Why to stop there

A reset restarts the control but cannot tell us whether the control or its wiring is responsible.
We check the connections first, then the cavity control, and name the one we find.
On an older oven we tell you straight if repairing it does not pay.

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

FC E3Whirlpool Over-the-range Microwave Showing FC E3 for Wi-Fi: Module Check FC E7Whirlpool OTR Microwave Connection Code FC E7: Appliance Not Reaching the Internet FC E8Whirlpool OTR Microwave Registration Code FC E8: Entry Mistake FCE8Whirlpool Over-the-range Microwave Registration, FCE8: Wrong Model Selected Feature Not Available or Fault DetectedWhirlpool Built-in Microwave Message "Feature Not Available": Retry or Cut Power LOCWhirlpool Microwave LOC on the Display: Control Lock Is On PFWhirlpool Over-the-range Microwave Showing PF: Power Failure Indicator Press Cancel to ResetWhirlpool Built-in Microwave Message "Press Cancel to Reset": Error Cleared by Cancel

F4F4 questions

What does F4 mean without an E and a number?

It points to the oven cavity control or its wiring. The guidance names nothing more specific, so a technician has to test that circuit to find the cause.

Is F4 E0 the same as F4?

No. F4 E0 names the microwave inverter, while plain F4 points to the cavity control. Each has its own explanation and its own first checks.

What happens after I reset the breaker?

If the display stays normal and the oven works, carry on. If F4 returns, repeated resets will not help, and we should test the control circuit.

Book a visit

Still seeing F4?

A technician diagnoses it on site and gives you the price in writing before any work starts.

(713) 589-6107