E04 error and no water flow through the softener, even though inlet valve is open.

Safety: Shut off water supply to the softener and relieve pressure by opening a downstream faucet. Unplug the unit.

Steps:

• Check bypass: Verify the AquaClean bypass valve is in the correct "Service" position, not in bypass.
• Inspect flow sensor: Locate the turbine/flow sensor at the inlet side of the valve head. Disconnect the harness and ensure the connector is clean and fully seated.
• Remove and clean: Remove the flow sensor body. Rinse under running water and remove any sand, iron, or scale. Ensure the turbine spins freely with a gentle puff of air.
• Check for damage: If the turbine blades are broken or the magnet is missing, the sensor must be replaced.
• Reassemble and test: Reinstall the sensor, restore water and power, and run water at a faucet. Confirm the display shows flow and that E04 clears.

If the error persists and the sensor is clean but not registering, replace the AquaClean flow sensor assembly.