Control valve display shows ERR1 and softener will not start a regeneration cycle

Safety first: Unplug the softener from power and close the inlet water valve before opening the control valve. Depressurize by running a nearby cold faucet for 30–60 seconds.

• Check for mechanical binding: Remove the control valve cover on the US Water Systems softener head (e.g., Matrixx, Flexx, or Fusion series). Inspect the main drive gear and cam. Look for broken teeth, debris, or salt bridging fragments that may have migrated into the valve.
• Inspect the piston and seals: Manually rotate the cam (if possible) to move the piston. If it is very hard to move or does not move at all, the piston/seal pack may be swollen or fouled with iron. Remove the piston and seal/spacer stack per the service manual and check for scoring or deformation.
• Test the drive motor: With power restored and the cover off, initiate a manual regeneration. Observe whether the motor attempts to turn. If the motor hums but does not rotate, or does nothing at all, test for 24 VAC (or specified voltage) at the motor leads. If voltage is present but the motor does not turn, replace the drive motor.
• Check wiring and board: Verify the motor harness is fully seated on the control board. Look for burnt traces or corrosion on the board. If the motor tests good but never receives power, the control board is likely defective and should be replaced.
• Reassemble and test: Reinstall the piston, seals, and cam, ensuring correct orientation. Restore water and power, then run a full manual regeneration to confirm ERR1 is cleared.