E03 displayed and regeneration stops mid-cycle

Safety first: Disconnect power and place the softener in bypass. Do not force the valve by hand with power connected.

• Inspect motor and gears: Remove the control cover to access the drive motor and cam/gear assembly. Look for broken teeth, cracked cam, or loose mounting screws. Replace damaged gears or cam.
• Check for mechanical binding: With power off, gently rotate the cam/rotor by hand (if the design allows). It should move smoothly through positions. If it binds, internal valve seals or pistons may be swollen or debris-laden and require service.
• Test motor operation: Restore power and start a manual regeneration. Observe whether the motor attempts to turn. Listen for humming without movement (indicates a seized motor). Replace the Watersoft drive motor if it does not run or stalls under light load.
• Inspect position switch/encoder: Many Watersoft valves use a microswitch or optical encoder to sense cam position. Check wiring to the switch/encoder and ensure the actuator tab on the cam is intact. Replace the position switch/encoder if it is loose, corroded, or not changing state as the cam rotates.
• Control reset: After repairs, perform a control reset per the Watersoft manual and run a full regeneration to verify that E03 does not recur.

Internal valve rebuild (pistons, seals, spacers) is more advanced and may be best handled by a Watersoft service professional.