BoilerFaultCodesYour boiler has shut down because it is unable to drain away the waste water it produces, causing a small internal reservoir to overflow.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Condensate pump over level switch activated - reservoir level too high resulting in ignition lockout.
What causes this fault?
This fault occurs when the boiler's internal drainage system becomes blocked, preventing the waste water produced during heating from leaving the unit. The most common reason is a buildup of debris in the condensate trap or a failure of the mechanical pump that pushes the water away. To prevent internal flooding and damage, a safety switch triggers and shuts the boiler down until the water level drops.
This fault is more common in winter, as the external pipe that carries the waste water away can freeze, causing water to back up into the boiler.
DIY fix possible
Locate the external white plastic drainage pipe and check if it has frozen or is blocked with debris.If frozen, gently pour warm (not boiling) water over the pipe to melt the ice block.Check that the condensate pump (if fitted) is plugged in and switched on.
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