Whirlpool · Washing Machine
Whirlpool Washing Machine F28 Error Code
Main and motor control not communicating
What this error means
F28 means the Central Control Unit lost serial communication with the Motor Control Unit. The washer cannot command drum rotation until both boards exchange data again. A two-minute power reset is the first recovery step.
How F28 is detected
When F28 appears on a Whirlpool washing machine, the control board has confirmed that water did not leave the machine within the programmed drain window. On Whirlpool WFW9150FW, Whirlpool WFW8620HC, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most F28 calls are resolved without parts: unplug the washer for two minutes to reset both control boards. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If F28 returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Loose ribbon or wire harness between CCU and MCU
- Corroded connector pins at the motor control board
- Failed motor control unit after overheating
- Failed main control board UART circuit
Step-by-step fixes
- 1Unplug the washer for two minutes to reset both control boards
- 2Remove the top panel and reseat the CCU-to-MCU communication harness
- 3Inspect connectors for bent pins or moisture at the MCU near the motor
- 4Run a quick diagnostic spin test—F28 during motor command confirms board-level failure
When to call a technician
CCU and MCU boards are expensive—have a technician isolate which board lost communication before ordering parts.
Affected models
- Whirlpool WFW9150FW
- Whirlpool WFW8620HC
- Whirlpool WFW9620HW
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use washing machines to prevent F28 from lint and food debris buildup.
- Record when F28 appears in the cycle and whether it clears after a 60-second power reset on your Whirlpool washing machine—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for F28; Whirlpool uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting F28; reversed plugs on pumps and valves cause immediate repeat faults.