BoilerFaultCodesYour boiler is failing to light the flame properly even though gas is reaching the unit, meaning you will have no heating or hot water until a technician inspects the internal components.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flame not detected. Gas present and at correct pressure. Combustion CO2 level. Condition of flue. Ignition electrodes. Ignition harness and connections. Flame sense harness. Flame sense cables and connections. Gas valve. Otherwise replace control board.
What causes this fault?
This fault occurs when the boiler's internal computer cannot confirm that a flame has been lit, even though it is trying to start. The most common reasons are that the spark electrodes have worn out and can no longer ignite the gas, or the sensor tasked with 'seeing' the flame has become dirty or faulty. In some cases, it may be due to a mechanical failure in the gas valve which prevents fuel from actually entering the burner.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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