Whirlpool Washer F28 Error Code: Serial Communication Fault
Quick Answer
Whirlpool F28 is a serial communication fault between the CCU (central control unit) and MCU (motor control unit) on older Duet front-load models. These two boards are in different locations: the CCU is behind the lower rear panel and the MCU is at the bottom of the washer near the motor. They communicate via a dedicated serial data wire in the main harness.
Whirlpool F28 is a serial communication fault between the CCU (central control unit) and MCU (motor control unit) on older Duet front-load models. These two boards are in different locations: the CCU is behind the lower rear panel and the MCU is at the bottom of the washer near the motor. They communicate via a dedicated serial data wire in the main harness. F28 most commonly occurs when the wire harness connector at either board becomes corroded or loose from vibration. On vintage Duets (2005-2010), the harness route passes near the drain pump, and water from a leaking pump can drip onto the MCU connector. Check both board connectors for corrosion before replacing either board.
What Does the F28 Code Mean?
F28 = CCU to MCU serial communication fault on older Duets. Check the wire harness connectors at both boards for corrosion. Water from drain pump leaks commonly drips on the MCU connector.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Symptoms You May Notice
- F28 on display
- Motor does not run at all
- Washer fills but does not agitate or spin
- May alternate between F28 and normal operation
- Drum does not move in any cycle phase
Can you reset a Whirlpool washer to clear the F28 code?
Unplug 5 minutes for full board reset. F28 often clears temporarily after a long power-off but returns because the connector corrosion is still present.
Tools Required for Diagnosis
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
Unplug
Unplug. Check the MCU connector at the bottom of the washer near the motor. Look for signs of water dripping from the drain pump area. If wet, dry thoroughly and check for drain pump leaks. Clean the connector pins with contact cleaner.
Check the CCU connector behind the lower rear panel
To determine which board failed
Replacement Parts
If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.
| Part Name | OEM Number | Estimated Price |
|---|---|---|
| Whirlpool MCU Motor Control BoardModel-specific · $100–$250 | Model-specific | $100 – $250 |
| Whirlpool CCU Central Control BoardModel-specific · $100–$200 | Model-specific | $100 – $200 |
| Contact CleanerN/A · $6–$10 | N/A | $6 – $10 |
Repair vs. Replace Calculator
Frequently Asked Questions
F28 comes and goes. Is my washer dying?
Is F28 the same as newer F6 or F7 codes?
Can water damage from a drain pump leak cause F28?
Related Whirlpool Washer Error Codes
Same Fix Works on These Brands
Whirlpool shares the same hardware platform with these brands. The diagnosis and repair steps are identical.
Models Known to Experience F28 Errors
This repair applies to most Whirlpool washers with this error code. Common model numbers include:
WFW9150WW, WFW9050XW, WFW8300SW, GHW9150PW, WFW9200SQ
Last verified for technical accuracy on March 15, 2026