A09
Ferroli
Flue Gas Temperature / Combustion Safety Fault
Boiler locks out with A09; may be associated with flue gas recirculation or combustion issues.
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
Blocked or restricted flue, Faulty flue gas thermostat or sensor, Incorrect combustion settings, Fan or air supply fault
How to Fix / Troubleshooting
Safety first: Do not operate the boiler if you suspect flue or combustion problems. Risk of carbon monoxide poisoning.
- External flue check: Ensure the flue terminal is unobstructed and correctly fitted. Do not alter the flue yourself.
- Reset once: If the error returns, stop using the boiler.
- Engineer checks:
- Inspect the entire flue system for blockages, disconnections, or incorrect slope.
- Test the flue gas thermostat or sensor and replace if faulty.
- Check fan operation and air intake path.
- Perform combustion analysis and adjust gas valve/CO₂ settings as per Ferroli specifications.
Advertisements
Repair Difficulty
Professional Required
5/5
Required Part
Flue Gas Thermostat / Sensor
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements