Frigidaire Range Error Code F27

F27 means the oven's User Interface board and Relay board cannot establish communication with each other. The UI board sends commands through connectors labeled MACS1 and MACS2, and the relay board receives them at J3 and J4. When this link fails to initialize, the oven displays F27 and will not operate. The cause is typically a loose connector, a wiring fault, or a failed control board.

Start by disconnecting power for 30 seconds and restoring it to see if the code clears. If it returns, inspect all connectors at the UI board (MACS1 and MACS2) and the relay board (J3 and J4) to make sure they are fully and firmly seated. Next, test the wiring continuity between those connection points. If wiring and connectors are intact, one or both control boards may need to be replaced.

If the fix is simply reseating a connector or replacing a damaged wire section, costs are minimal, generally under $50 including any needed supplies. If the User Interface board or Relay board needs replacement, parts and labor can range from $150 to $400 or more depending on the specific model and whether a professional technician is hired. Getting a diagnosis before ordering parts is recommended to avoid replacing the wrong board.

A power reset will sometimes clear F27 if the fault was caused by a temporary electrical disturbance. To reset, disconnect the range from power, wait at least 30 seconds, then restore power. If the F27 code returns after the reset, a wiring or component problem is present and will require further diagnosis.

When F27 is active, the oven cannot properly communicate between its control boards, meaning it cannot reliably control heating elements or other functions. You should not attempt to use the range while this code is displayed. Disconnect the appliance from power until the fault has been diagnosed and repaired.