KitchenAid Over-the-Range Microwave Code F6: Relay control board

What F6 means

On KitchenAid over-the-range microwave hood combinations such as the KMLS311HSS or KHMS155LSS, F6 means the relay control board, or the wiring serving it, may have a problem. The relay board switches power to the magnetron, fan and lamp. When it misbehaves, the display shows F6 and the microwave usually stops heating. The fan and light may keep running even though the heating has stopped, which is normal for this kind of board issue.

Common causes of F6

Relay control board that is not switching loads correctly
Wiring or connector to the relay board that is loose or damaged

✓ One safe check you can try

1. Press Cancel and watch what the display does next. 2. Unplug the microwave, or switch off its breaker, for a full minute and restore power. 3. Check that the vent fan and light still respond. 4. Start a short cycle with a cup of water; if F6 returns, stop using the unit and call.

! Why to stop there

Relay boards sit in the electronics area with mains voltage on them.
Replacing the wrong board is an expensive mistake, so we test first.
The price is quoted in writing before work, and our repair has a 30-day workmanship warranty.

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.

→Same appliance

Other Microwave codes

Probe or Insert ProbeKitchenAid Combination Microwave Message "Probe" or "Insert Probe": Seat the meat probe in its jack PUSH or PSHKitchenAid Built-In Microwave Message PUSH or PSH: The oven is waiting for Start Registration ErrorKitchenAid Over-the-Range Microwave Message "Registration Error": Check the home network and try again Sabbath, Sab, 5Ab, or 5A6KitchenAid Built-In Microwave Display Sabbath, Sab, 5Ab or 5A6: Sabbath Mode is on SEKitchenAid Over-the-Range Microwave Code SE: Keypad or user interface problem F6 E7KitchenAid Combination Microwave Code F6 E7: Manager board for the upper cavity FC E7KitchenAid Over-the-Range Microwave Code FC E7: Appliance did not join the router F6 E8KitchenAid Combination Microwave Code F6 E8: Manager control stopped responding

F6F6 questions

What does the relay board do?

It acts as a set of switches for the microwave's heating, fan and lighting loads. If it cannot switch properly, the control stops the cycle and shows F6.

Will the hood fan still work?

Sometimes, because the relay board feeds several functions. Do not rely on it, and stop if you notice odd smells or noises while F6 is shown.

Is F6 the same on a built-in microwave?

No. Built-in units pair similar letters with an oven control message. The over-the-range F6 is specifically the relay control board. The over-the-range version names the relay board specifically, while built-in units show different wording.