Display shows “Err 10” and backwash step does not start or complete

Safety: Disconnect power and place the softener in bypass. Relieve pressure before removing the drain line.

Steps:

• 1. Inspect drain line: Check the drain hose from the Sterling valve to the drain. Ensure it is not kinked, frozen, or blocked. Clear any obstructions.
• 2. Check drain flow control: Remove and clean the backwash/drain flow control button or orifice in the valve body. Rinse thoroughly to remove iron and debris.
• 3. Examine piston movement: Remove the valve motor and manually move the piston/rotor through its stroke. If it binds in the backwash position, rebuild the valve with a seal and spacer kit.
• 4. Test motor: If the piston moves freely by hand but not under power, test or replace the valve motor.
• 5. Reassemble and test: Restore power, take the unit out of bypass, and run a manual regeneration to confirm backwash starts and completes without Err 10.