BoilerFaultCodesYour boiler's waste water pipe is blocked or frozen, preventing the system from draining properly and causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Condense trap/pipe has become blocked.
What causes this fault?
This fault occurs when the liquid produced by the boiler during operation cannot flow away, causing it to back up into the system. The most common reason is a blockage in the drainage pipe, often caused by a buildup of debris in the internal trap or ice forming in the external pipework.
This fault is significantly more common during winter, as the external condensate pipe can easily freeze during cold spells and prevent water from leaving the boiler.
DIY fix possible
Locate the plastic pipe leading from the boiler to the outside drain.Check if the pipe is frozen and gently pour warm (not boiling) water over it to thaw.Ensure the internal trap or collection bottle is not full of debris.Reset the boiler once the blockage is cleared.
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