Technical description
Burner does not operate at or near minimum gas pressure
What causes this fault?
This fault occurs when the boiler struggles to maintain a steady flame while running at its lowest power level, often during the ignition sequence. The most common reasons are a malfunctioning gas valve that cannot regulate fuel flow accurately or worn ignition electrodes that fail to detect the flame, causing the system to shut down for safety.
This issue is more frequent during the first cold spells of autumn, when the boiler is asked to fire up after long periods of inactivity during the summer.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.