Display shows E02 and the unit remains in service mode without regenerating

Safety: Isolate the softener with inlet/outlet valves and disconnect power before removing the flow meter assembly.

• Check wiring: Remove the front cover of the Cillit control head. Locate the flow sensor connector (usually a 2–3 wire plug near the inlet). Ensure it is fully seated and wires are not pinched or broken.
• Clean turbine: Shut off water, relieve pressure, then unscrew the flow meter housing from the valve body (on many Cillit models it is mounted on the inlet side). Carefully remove the turbine wheel. Rinse under clean water and remove any grit or iron deposits. Ensure the turbine spins freely on its shaft.
• Inspect Hall sensor: Check the small electronic sensor on the flow meter body for cracks or water ingress. If corroded or swollen, it must be replaced.
• Reassemble and test: Refit the turbine and O‑ring, tighten the housing evenly, restore water and power. Enter the diagnostic menu (if available) and run a flow test by opening a tap; verify that the controller registers flow.
• Replace if needed: If no pulses are detected despite good wiring and a clean turbine, replace the complete Cillit flow meter / turbine assembly with the correct model‑specific part.