Heater locks out with E09, often accompanied by unusual noises from the combustion area.
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.
Possible Causes
How to Fix / Troubleshooting
Critical safety warning: Gas valve faults must be handled by a licensed gas technician. Do not attempt to open, adjust, or replace the gas valve yourself.
User-level checks:
- Reset the unit: Attempt a single reset as per the manual. If E09 returns, do not continue resetting.
- Visual inspection: With power off, remove the front cover and visually inspect the gas valve wiring harness. Ensure the plug is fully seated and there are no obvious burn marks or damaged wires.
Professional work only: A technician will measure gas valve coil resistance, verify modulation signals from the PCB, check gas pressures, and replace the Baxi gas valve or PCB as required.
Repair Difficulty
Required Part
We may earn a commission from links on this page.