Whirlpool Microwave F6 Error Code — What It Means
The F6 error code on a Whirlpool over-the-range microwave means the appliance could not complete the commanded function. Whirlpool’s published guidance points to a problem with the relay control board or the associated wiring between the board and other components. The microwave will stop working, may not start at all, or will lock out and display F6 immediately when you try to use it.
Common Causes
- Failed relay control board A relay on the control board or the entire relay control board has failed and cannot complete the microwave’s operational sequence.
- Loose or damaged wiring connectors Wire harness connections between the relay control board and other components have come loose, corroded, or burned.
- Bad microwave relay on the microcomputer board The relay that controls microwave operation is soldered to the main control board and has failed internally.
- Heat-damaged wiring or terminals Heat discoloration or charring at the control-board connectors indicates failed contacts that prevent proper relay control.
Step-by-Step Fix
- Turn off power at the circuit breaker(s) serving the microwave and wait one full minute to allow the control board to reset.
- Restore power and attempt to run a short cook cycle to see if the F6 code returns within the next minute of operation.
- If the code returns, disconnect power again and remove the outer cover or access panel to expose the relay control board and wiring harnesses.
- Inspect the relay control board and all wire connectors for loose terminals, burn marks, heat discoloration, or corrosion at the plug contacts.
- Check the wiring harness running from the relay board to the magnetron and other load components for broken insulation or damaged wires.
- Replace the relay control board (or the full microcomputer board assembly if the relay is integral) if you find heat damage, visible relay failure, or if all wiring checks out but the fault persists.
- Reassemble the cabinet, restore power, and run a full heat cycle to confirm the microwave operates normally without the F6 code reappearing.
Parts Often Needed
| Part | Notes |
|---|---|
| Relay Control Board | Amazon | The primary component Whirlpool identifies for F6 faults. Match the board part number to your microwave model. |
| Microcomputer Control Board Assembly | Amazon | Used when the relay is integrated into the main control board rather than a separate relay module. |
| Wiring Harness | Amazon | Order a replacement harness if connectors are melted, charred, or terminals are corroded beyond cleaning. |
When to Call a Pro
Call a qualified appliance technician if you are not comfortable working inside a microwave cabinet. Even with power disconnected, the high-voltage capacitor can retain a lethal charge for days. If you have inspected the relay board and wiring and found no obvious damage but the F6 code persists, a technician with proper discharge tools and a multimeter can safely isolate the fault and confirm whether the relay, control board, or another component is responsible.