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Whirlpool · Washing Machine

F28

Serial Communication Error

Severity
High

The error code F28 on your Whirlpool Washing Machine indicates a specific system failure categorized as "Serial Communication Error". This guide walks you through the most likely causes and the correct repair sequence.

Owner's Summary

The two main computer boards in your Whirlpool washer have lost communication. A power cycle often resolves this if it was caused by a voltage spike. If it returns every time, a board replacement will be needed.

Symptoms

Whirlpool washer all lights flashing, stops suddenly, F28 displayed

Common Causes

  • Loose wiring harness between CCU and MCU
  • Power surge damaging communication circuit
  • Defective CCU (Central Control Unit)
  • Defective MCU (Motor Control Unit)

How to Fix

  1. 1 Unplug washer for 5 minutes and reconnect power
  2. 2 Inspect all wiring harness connections between CCU and MCU
  3. 3 Test CCU and MCU for voltage and communication signals
  4. 4 Replace CCU if internal fault is confirmed
  5. 5 Replace MCU if motor communication is lost

Tools You'll Need

Multimeter Flashlight

Most of these fixes need only basic hand tools. If your repair requires opening electrical housings or testing live components, a multimeter and basic electrical safety knowledge are essential — when in doubt, call a technician.

Technical Explanation

The CCU and MCU communicate over a dedicated serial data line. The CCU expects periodic heartbeat packets from the MCU during operation. If 3 consecutive communication windows pass without a valid response, the CCU posts F28 and disables all outputs.

Is It Safe to Keep Using?

Safe to leave off. Do not attempt to force cycles with F28 active.

Technician's Pro Tip

Before replacing boards, trace the wiring harness between CCU and MCU — on Whirlpool front-loaders this harness runs along the back of the machine and is prone to chafing on the cabinet edge. A $3 section of wire loom and some tape can fix this for free.

Related Codes

E2 — Samsung Washing Machine

Water Supply Error

High
4E — Samsung Washing Machine

No Water Supply Detected

High
5E — Samsung Washing Machine

Drain Error — Water Not Draining

High

Frequently Asked Questions

What does error code F28 mean on a Whirlpool Washing Machine?
Code F28 on a Whirlpool Washing Machine indicates "Serial Communication Error." In practice, the most common trigger is loose wiring harness between CCU and MCU. Severity is rated high, and typical repair costs range from $0 to $350.
Can I fix F28 myself, or do I need a technician?
Many cases of F28 can be resolved without a technician. The first step to try: unplug washer for 5 minutes and reconnect power. If that doesn't clear the code, work through the remaining steps in the "How to Fix" section above before assuming a part needs replacing.
Is it safe to keep using my washing machine with code F28 showing?
Safe to leave off. Do not attempt to force cycles with F28 active.
How much does it cost to repair F28 on a Whirlpool Washing Machine?
Repair costs for code F28 typically range from $0 to $350. Connector reseat: $0; CCU: $80–$200; MCU: $100–$350. Costs on the low end usually reflect a DIY fix with no parts required, while the high end reflects a part replacement plus professional labor.
Estimated Repair Cost USD
$0 – $350

Connector reseat: $0; CCU: $80–$200; MCU: $100–$350