E09
State
Flow Sensor / Turbine Fault
State tankless water heater displays E09; unit may not detect water flow or may shut off unexpectedly.
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 turbine, Debris in cold water inlet, Failed flow sensor, Damaged sensor wiring
How to Fix / Troubleshooting
Safety: Turn off power and close the cold water supply to the heater. Relieve pressure by opening a hot water tap.
- Clean inlet filter: Remove and clean the cold inlet filter screen. Flush debris from the line.
- Access flow sensor: Locate the flow sensor assembly on the cold inlet manifold. Remove per the State service instructions.
- Inspect turbine: Check that the turbine spins freely. Remove scale or debris with a soft brush. Do not use harsh chemicals that can damage plastic.
- Reassemble and test: Reinstall the flow sensor, restore water and power, and test. If E09 persists, replace the flow sensor assembly.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Flow Sensor Assembly
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements