Display shows “Err 05” and unit remains in backwash or fails to advance out of backwash.

Safety first: Disconnect power and place the softener in BYPASS. Relieve pressure by opening a faucet.

Inspection:

• Remove the controller cover to access the cam/position switch assembly.
• Visually inspect the cam for cracks, missing lobes, or misalignment with the control disc.
• Check that the position switch or sensor is firmly mounted and actuated by the cam as the disc rotates.
• Inspect the wiring harness from the sensor to the controller for damage or loose connectors.

Functional test:

• With power restored and extreme caution, initiate a manual regeneration and observe whether the cam rotates and actuates the switch.
• If the cam rotates but the controller does not detect position changes, the position sensor/switch is likely defective.
• If the cam does not rotate, the issue may be with the drive motor (see motor fault) rather than the sensor.

Resolution: Replace the cam/position switch assembly or the entire control head if parts are not individually serviceable. Proper indexing of the cam to the valve positions is critical; consult a Kinetico service manual or technician.