Alpha Flame Instability / Short Cycling

Boiler ignites but shuts down after a few seconds without showing a specific error code.

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

Incorrect gas pressure, Partially blocked burner, Faulty flame sensor, Poor earth connection

Safety: Gas adjustments must only be made by a Gas Safe registered engineer.

Check flue terminal: Ensure the flue outlet is not obstructed, which can affect combustion stability.
Reset boiler: Perform a reset and observe the ignition sequence. Note any unusual noises or smells.
Flame sensor cleaning (qualified person): Clean the ionisation electrode and ensure it is correctly positioned.
Professional combustion check: An engineer should check inlet gas pressure, burner condition, and perform a flue gas analysis.

Professional Required 5/5

Burner Assembly

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