Safety: Disconnect power before working on wiring or sensors.

Check wiring: Trace the cable from the flow meter on the Idrobase valve body to the control board. Ensure the connector is fully seated and wires are not cut or pinched.
Clean flow meter: Shut off water and relieve pressure. Remove the flow meter cartridge or body. Inspect the turbine or paddle wheel for scale or debris. Clean with a soft brush and descaling solution. Ensure free rotation.
Controller settings: Enter the installer menu (refer to Idrobase manual) and verify the correct flow meter type and pulse value are selected. Incorrect settings can trigger E04.
Signal test: With power off, disconnect the flow meter and measure resistance across the sensor (for reed or Hall types). Compare to specification. If open or shorted, replace the flow meter.
Final check: Reassemble, restore water and power, and run water through a tap. Confirm that the display shows flow or counts down capacity. If not, replace the flow meter assembly.

Display shows E04 and unit remains in service mode without regenerating

Possible Causes