Boiler starts then shuts down after a few seconds, repeatedly, without showing an error code.
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: This is a combustion-related issue; only a qualified gas engineer should adjust gas settings or work on the burner.
User-level checks:
- Note any patterns (e.g. only in windy conditions) and report to the engineer.
Technical checks (qualified personnel):
- Clean the burner and check for corrosion or blockage.
- Inspect and clean the flame sensor; ensure correct positioning in the flame.
- Verify boiler earthing and bonding.
- Check gas inlet and burner pressures and adjust the gas valve as per manufacturer’s data.
After repair, confirm stable ignition and flame retention in both CH and DHW modes.
Repair Difficulty
Required Part
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