Code 15 appears, boiler locks out, may be related to flue gas temperature
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
Safety first: High flue gas temperatures can be dangerous. Turn off the boiler and do not operate it until the cause is identified. Only qualified technicians should work on the flue and combustion system.
Technician steps:
- Inspect flue system: Check the entire Intergas flue for blockages, disconnections, or incorrect slope. Ensure terminal clearances meet manufacturer requirements.
- Check flue gas sensor: Locate the flue gas temperature sensor (if fitted) and inspect wiring and mounting. Replace if readings are clearly incorrect.
- Verify combustion: Perform a combustion analysis and confirm CO₂/O₂ values are within Intergas specifications. Adjust gas valve settings if necessary.
- Check fan speed: Ensure the fan is achieving the correct speed and that the venturi is not blocked.
Do not bypass or disable any safety sensors. If in doubt, leave the boiler off and consult Intergas technical support.
Repair Difficulty
Required Part
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