Control displays “Err 04” and time-of-day or capacity settings reset frequently

Safety first: Disconnect power before removing the control panel cover.

Step-by-step checks:

• 1. Verify power source:
  • Confirm the outlet has stable 120V AC using a plug-in tester or another appliance.
  • Inspect the Kenmore power adapter/transformer for heat damage, cracks, or a loose plug.
• 2. Inspect control connections:
  • Remove the control panel cover.
  • Check the low-voltage connector from the transformer to the control board for tight fit and no corrosion.
  • Reseat all connectors on the board.
• 3. Reset and reprogram:
  • With power restored, perform a soft reset (unplug for 5 minutes, then plug back in).
  • Re-enter time, hardness, and capacity settings per the user manual.
  • Monitor for recurrence of Err 04 or loss of settings.
• 4. Replace components:
  • If the transformer is not outputting correct low voltage (typically 24V AC) or is hot/noisy, replace the power transformer.
  • If power is stable but Err 04 persists and settings are lost, replace the electronic control board.