E03 error and softener stuck in regeneration cycle

Safety: Unplug the softener or switch off its circuit. Close the inlet and outlet bypass valves to isolate the unit.

• Listen for motor: With the cover removed and power briefly restored, start a manual regeneration. If you do not hear the drive motor running, power off and continue diagnosis.
• Inspect cam and rotor: Remove the control head cover. Check the main cam/gear for broken teeth, foreign objects, or binding. Manually rotate the cam slightly (with power off) to feel for mechanical jams.
• Check motor wiring: Verify the motor connector is fully seated on the control board and that no wires are damaged or burnt.
• Test motor continuity: Disconnect the motor and measure resistance across its terminals. An open circuit indicates a failed motor that must be replaced.
• Inspect position switch: Locate the cam or position switch (often a microswitch or Hall sensor). Ensure it is firmly mounted and actuated by the cam. Replace if physically damaged or if the control never detects position changes.
• Reassemble and test: Refit all parts, restore water and power, and run a full regeneration. If E03 returns, the control board may be defective and require replacement.