Display shows “Err 4”; unit may not sense water flow correctly and may not regenerate at the right time.

Safety first: Shut off the inlet valve and depressurize the system by opening a nearby soft water faucet. Unplug the softener.

• Step 1 – Check for flow reading: With the unit powered, run water in the house and watch the display. If the flow indicator does not change, the turbine may not be spinning or the sensor is faulty.
• Step 2 – Remove turbine assembly: Disconnect plumbing if needed and remove the bypass valve from the softener. Access the turbine housing on the inlet side of the valve head. Carefully pull out the turbine and shaft.
• Step 3 – Clean turbine: Rinse the turbine and shaft under running water. Remove iron, sand, or scale buildup. Ensure the turbine spins freely on the shaft.
• Step 4 – Inspect sensor and wiring: Check the small Hall‑effect sensor above the turbine for cracks or corrosion. Verify the harness is fully seated at both the sensor and control board.
• Step 5 – Replace parts if needed: If the turbine is damaged or swollen, replace the GE turbine and shaft assembly. If the sensor tests open or the error persists, replace the GE turbine sensor.
• Final step: Reassemble, restore water and power, and verify that the display shows flow when a faucet is opened.