Appliance Tech Info

Service Information For Appliance Repair Professionals

Appliance Control Unit (ACU) and Human Machine Interface (HMI) Replacement

Manufacturer(s)

  • Whirlpool
  • Maytag

Appliance Type(s)

  • Top load washers and matching dryers

Model(s) Included

Washer models (Whirlpool):

  • WTW5100H*
  • WTW5105H*
  • WTW6120H*
  • WTW7120H*
  • WTW8120H*

Washer models (Maytag):

  • MVW6230H*
  • MVW6230R*
  • MVW7230H*
  • MVW7232H*
  • MVW8230H*

Dryer models (Whirlpool):

  • WED5100H*
  • WED6120H*
  • WED7120H*
  • WED8120H*
  • WGD5100H*
  • WGD6120H*
  • WGD7120H*
  • WGD8120H*
  • YWED5100H*
  • YWED6120H*
  • YWED7120H*

Dryer models (Maytag):

  • MED6230H*
  • MED6230RH*
  • MED7230H*
  • MED8230H*
  • MGD6230H*
  • MGD6230RH*
  • MGD7230H*
  • MGD8230H*
  • YMED6230H*
  • YMED7230H*
  • YMED8230H*

Serial numbers: Washers and dryers starting with M947xxxxx

Symptom(s)

Machine may not operate after both the Human Machine Interface (HMI) and Appliance Control Unit (ACU) are replaced at the same time.

Possible Cause(s)

The model, settings information, and serial number are stored in both the HMI and ACU boards. This data is published from one board to the other when only one control is replaced. When both controls are replaced simultaneously the information is lost and the unit may fail to operate.

Diagnostic Procedure

Confirm the unit is one of the listed models and serial number ranges. Verify that both the HMI and ACU were recently replaced together. Check whether the machine powers on, responds to controls, or displays any operation after dual replacement. If original boards are still available note their presence for recovery steps.

Always disconnect power before servicing. Replace all parts and panels before operating. Failure to follow these steps can result in death or electrical shock.

Recommended Repair

When both controls must be replaced follow this sequence:

  1. First replace the Human Machine Interface (HMI). Refer to the technical manual for removal and installation details.
  2. Power up the unit and wait 3 minutes. This allows the model, settings information, and serial number to publish to the remaining control board.
  3. Remove power from the unit.
  4. Replace the Appliance Control Unit (ACU). Refer to the technical manual for details.
  5. Power up the unit.

If both controls were already replaced together and the machine is inoperable use one of the recovery options below.

Option 1 (all models):

  • If one of the original controls is still available, temporarily reinstall an original part and repower the machine.
    • Prefer reinstalling the original HMI first when both originals are on hand.
  • This writes the model, settings, and serial number to the other board.
  • Reinstall the new control.

Option 2 (5100-series Whirlpool or 6000-series Maytag models only):

  • Plug and unplug the power cord or flip the breaker five times.
  • The machine will default to the correct model, features, and settings.

This tech tip is based directly on Technical Service Pointer W11498806 Rev B for quick field reference by certified appliance repair technicians.