BoilerFaultCodesYour boiler has stopped working because it cannot light the flame or the internal drainage pipe is backed up with water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flame Failure or Blocked Condensate Drain
What causes this fault?
This fault occurs when the boiler tries to light but fails to detect a steady flame, or when the internal drain for waste water becomes blocked. The most common reason is a buildup of debris in the condensate trap or a worn-out ignition spark causing a failed startup. If the waste pipe is blocked, the boiler shuts down as a safety precaution to prevent water from backing up into the combustion chamber.
This fault is significantly more common during freezing winter spells, as the external condensate pipe can freeze, causing water to back up and trigger the sensor.
DIY fix possible
Check if your gas prepay meter has credit and that the external gas stopcock is open.Inspect the plastic condensate pipe outside for signs of freezing or blockage; gently pour warm water over it if frozen.Turn the selector switch to the reset position for five seconds, then turn it back to the 'on' position.
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