Whirlpool Microwave F1E4 Error Code: Control Board or Microwave Relay Fault

What the code means

Whirlpool's Product Help article for F1E4 on over-the-range microwaves says the oven could not execute the function and that there may be a problem with the Appliance Control Board or the associated wiring. Its only owner step is a power reset: turn off the circuit breaker for one minute, turn it back on, monitor the microwave for one minute to make sure the code does not return, then verify operation. The technician sheets inside these microwaves are more specific, and they differ by model. Tech sheets W11279380 and W11463265 list F1E4 as an MW Relay failure: check the wiring to relay 4903 on the control board and check whether that relay's contacts have welded closed, then, if the problem persists, check the door (P2-2), neutral (P1-3) and line (P1-1) voltages against the board's pin voltage matrix. Tech sheet W11268412 lists F1E4 as a Microwave ACU PCBA failure with a single repair, replace the control board, and the newer touch-screen sheet W11381054 says the same (Microwave ACU failure, replace ACU). Either way, the code sits on the main control board side of the microwave, not on a part an owner can service. Every one of these sheets also notes that many failure codes clear with a one-minute power cycle, which is why that is the first step. F4E4, the humidity sensor error, is a different code with its own test.

Likely causes

• A temporary control glitch, which Whirlpool's sheets say a one-minute power cycle often clears
• A failed appliance control board (ACU), the repair named on tech sheets W11268412 and W11381054
• A microwave power relay (relay 4903 on the control board) whose contacts have welded closed, on models covered by tech sheets W11279380 and W11463265
• Loose or damaged wiring to the relay or control board
• A door, line or neutral voltage problem at the control board, which the relay procedure checks if the fault persists

Safe DIY checks

1. Turn off the microwave's circuit breaker (or unplug it if you can reach the plug) for one full minute, then turn it back on.
2. Watch the display for about a minute with the microwave idle. If F1E4 does not come back, try a short timed heat with a cup of water to confirm it works.
3. If F1E4 returns, stop using the microwave and leave it off at the breaker until it is repaired. A relay stuck closed is not something to keep testing.
4. Note your model number from the label (usually inside the door frame) before you call, since the repair depends on which tech sheet your model uses.
5. Don't remove the cabinet or control panel to look at the board. Microwaves hold a high-voltage capacitor that can stay charged even when unplugged.

Parts that commonly fix it

Always match the part number to your exact model.

Related codes

• F6 Whirlpool Microwave F6
• E-11 Frigidaire Microwave E-11
• F3 GE Microwave F3
• F4 GE Microwave F4
• PF GE Microwave PF

All Whirlpool codes →

Sources

1. Whirlpool Product Help: F1E4 - Error Code - Over-the-Range Microwave (could not execute the function, control board or wiring, one-minute breaker reset, 1-866-698-2538)
2. Whirlpool Tech Sheet W11279380 Rev C (F1E4 MW Relay: check wiring to relay 4903, check for welded contacts, ACU pin voltage matrix)
3. Whirlpool Tech Sheet W11463265 Rev A (same F1E4 MW Relay procedure)
4. Whirlpool Tech Sheet W11268412 Rev A (F1E4 Microwave ACU PCBA failure, replace ACU PCBA)
5. Whirlpool Tech Sheet W11381054 Rev A (F1E4 Microwave ACU failure, replace ACU)