41
Rinnai
Flow Sensor Fault
Boiler displays error 41 and will not operate; may occur after wiring work or component replacement.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Stuck or scaled flow sensor turbine, Disconnected or damaged flow sensor wiring, Incorrect flow sensor installation, Faulty flow sensor
How to Fix / Troubleshooting
Safety first: Turn off power and isolate water supply to the boiler. Relieve pressure before opening any water connections.
- Locate flow sensor: The flow sensor is usually installed on the cold water inlet or system return line inside the boiler.
- Check electrical connection: Ensure the flow sensor plug is fully seated and wiring is intact.
- Clean or replace sensor: Remove the flow sensor following the service manual. Inspect for debris or scale on the turbine. Rinse with clean water and gently free any stuck parts. If damaged, replace the sensor.
- Reassemble and test: Refit the sensor, restore water and power, bleed air, and reset the boiler. Confirm that the boiler recognizes flow when taps or heating circuits are opened.
Advertisements
Repair Difficulty
Medium
3/5
Advertisements