Display shows “Err 8” and the unit may be stuck in regeneration or fail to complete a cycle.

Safety first: Unplug the unit and place it in bypass before working on the valve.

• Step 1 – Note when error occurs: Observe at which stage (backwash, brine draw, rinse) the error appears. This helps identify where the valve is binding.
• Step 2 – Inspect cam and switch: Remove the control cover and locate the cam position switch or sensor. Check that the cam lobes are intact and that the switch actuator rides correctly on the cam.
• Step 3 – Check wiring: Verify the position switch harness is firmly connected to the control board and not damaged.
• Step 4 – Manually advance valve: With power off, gently rotate the cam through all positions. If it binds at one point, inspect the valve body for internal damage or debris.
• Step 5 – Replace faulty components: Replace a defective cam position switch or damaged rotor/cam assembly. If the board is not energizing the motor at the correct times, replace the electronic control board.

Warning: Do not force the cam; excessive force can crack the valve body.