Boiler displays 08, no heating or hot water, may indicate flue/air fault
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: Do not operate the boiler with suspected flue issues. Isolate power and gas. Flue work must be carried out by a Gas Safe engineer.
- External flue check: From outside, ensure the flue terminal is clear and correctly supported. Look for signs of staining or leaks around joints.
- Condensate check: Ensure the condensate trap and pipe are not blocked or frozen, as this can affect combustion and pressure readings.
- Engineer tasks:
- Inspect and clear the venturi and pressure tubes.
- Test the air pressure switch operation under fan pressure.
- Verify flue length, routing, and terminal position comply with Vokera installation instructions.
Do not attempt to bypass or bridge the air pressure switch; this is a critical safety device.
Repair Difficulty
Required Part
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