E05 displayed and the unit does not detect water flow even when taps are open.

Safety first: Turn off power and close the bypass valves before removing any flow sensor components.

Step-by-step:

• 1. Confirm actual flow: Open a cold faucet downstream of the softener. If water flows normally but the display shows 0 gpm/Lpm, the sensor is not reporting.
• 2. Inspect sensor wiring: Locate the AquaHouse flow sensor (often at the outlet side of the control valve). Check the small cable from the sensor to the PCB for cuts, pinches, or loose connectors. Reseat the plug on the board.
• 3. Clean the turbine: Bypass and depressurize the softener. Remove the flow sensor housing or outlet adapter. Carefully pull out the turbine/impeller. Rinse away iron, sand, or scale. Ensure it spins freely on its shaft and reinstall in the correct orientation.
• 4. Check installation direction: Verify the arrow on the flow sensor body points in the direction of water flow (from inlet to outlet). Correct if reversed.
• 5. Test operation: Return to SERVICE, restore power, and run water. Watch the display for flow indication. If E05 remains, the sensor itself may be defective.

Replace the AquaHouse flow sensor assembly if cleaning and wiring checks do not restore proper readings.