Control head display shows E1 and system will not start a regeneration cycle

Safety first: Shut off water to the softener using the inlet and outlet shutoff valves. Place the bypass valve in BYPASS. Unplug the power adapter before opening the control head.

Steps to troubleshoot E1 (flow sensor):

• 1. Power-cycle the unit: Plug the unit back in after 2–3 minutes. If E1 clears temporarily and returns when water flows, continue below.
• 2. Check for obvious leaks or kinks: Inspect the inlet line and the Aquasana bypass assembly for kinks or crushed tubing that could affect the turbine.
• 3. Inspect the flow sensor/turbine: Remove the control head cover. Locate the small turbine/flow sensor assembly on the inlet side of the Aquasana control valve. Carefully remove it (note O-ring position). Rinse under clean water and remove any sand, scale, or debris.
• 4. Check wiring: Verify the flow sensor’s two- or three-wire harness is fully seated on the control board connector and that no wires are pinched or broken.
• 5. Reassemble and test: Reinstall the turbine, ensuring O-rings are lubricated with silicone grease and seated. Restore water (take unit out of BYPASS slowly), then plug in power and run a manual regeneration to confirm the error is cleared.
• 6. If E1 persists: The flow sensor or control board is likely defective. Replace the inlet flow sensor/turbine assembly. If a new sensor does not resolve it, the electronic control head may need replacement and should be serviced by a technician.