Display shows ERR 02 and regeneration stops mid-cycle; valve does not reach next position.

Safety: Disconnect power before working inside the control head. Close inlet and outlet valves if you need to remove the valve cover.

• Access the switch: Remove the control valve cover. Locate the small micro-switch or optical sensor that rides against the cam/gear on the Pentair valve.
• Check alignment: Verify the switch actuator arm is correctly contacting the cam lobe. If bent or out of place, gently bend it back so it clicks as the cam rotates.
• Electrical test: With power disconnected, unplug the switch connector. Use a multimeter in continuity mode across the switch terminals while manually rotating the cam. You should see continuity open and close as the cam passes. If not, the switch is faulty.
• Inspect wiring: Follow the harness from the switch to the control board. Look for pinched, broken, or corroded wires and reseat the connector on the board.
• Replace components as needed: If the switch fails continuity tests, replace the Pentair valve position switch. If the cam is cracked or missing lobes, replace the Pentair cam/gear assembly.
• Reset and test: Reassemble, restore power, clear the error (if your model supports reset), and run a manual regeneration to confirm the valve now indexes correctly.