E04 displayed and the Amfa4000 shows no flow even when water is being used in the house

Safety first: Turn off power before removing covers. Close the inlet valve if you will open any water connections.

• 1. Confirm actual water flow: Open a cold tap downstream of the Amfa4000. If there is no water, the issue is not the flow sensor but the water supply or bypass setting.
• 2. Check bypass/manifold position: Verify the Amfa4000 bypass valve is in Service position, not in Bypass or Isolate.
• 3. Inspect flow sensor wiring: Remove the control head cover and locate the flow sensor connector (usually a small 2–3 wire plug leading to the outlet manifold). Ensure it is firmly seated and the cable is not damaged.
• 4. Clean the turbine chamber: Shut off inlet and outlet valves and relieve pressure. Remove the outlet union and carefully access the turbine housing on the Amfa4000 outlet manifold. Rinse out any debris or scale and ensure the turbine spins freely when blown on gently.
• 5. Reassemble and test: Reconnect the outlet, open valves slowly, check for leaks, then restore power. Run water at a tap and verify the display shows flow and that E04 clears.

If the turbine spins freely and wiring is intact but E04 remains, the flow sensor or main control board may need replacement.