Display shows “Err 3”; softener may stay in one position (e.g., backwash or brine) and not advance.

Safety first: Disconnect power and shut off water supply before opening the valve head.

• Step 1 – Inspect cam and switch: Remove the top cover. Locate the cam assembly attached to the rotor shaft and the small position switch that rides on the cam. Check for broken cam lobes or a bent switch lever.
• Step 2 – Check alignment: Ensure the cam is firmly attached to the rotor shaft and not slipping. Tighten the cam set screw if loose.
• Step 3 – Test continuity: With the unit unplugged, disconnect the position switch harness and use a multimeter to check continuity while manually rotating the cam. The switch should open and close as the cam turns.
• Step 4 – Repair wiring: Inspect the harness from the switch to the control board for pinched or broken wires. Repair or replace as needed.
• Step 5 – Replace faulty parts: If the switch does not change state when actuated, replace the GE cam position switch. If the cam is cracked or worn, replace the GE cam and gear kit.
• Final check: Reassemble, restore water and power, and run a manual regeneration to confirm the error is cleared.