BoilerFaultCodesYour boiler has detected a blockage in the drainage pipe or an issue with the flue, preventing exhaust gases or water from leaving the system safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault: Condensate or smoke
What causes this fault?
This fault occurs when the boiler's internal sensors detect a backup of liquid or exhaust gases that cannot escape the system safely. The most common reason is a blockage in the condensate trap or a failure in the external drainage pipe, which causes water to fill up inside the heat exchanger. In some cases, it can also be triggered if the flue becomes obstructed or if the internal seals have perished, allowing smoke to recirculate.
This fault is significantly more common during freezing winter temperatures, as the external condensate pipe can freeze, causing liquid to back up into the boiler.
DIY fix possible
Check the white plastic pipe leading outside (condensate pipe) to see if it is frozen during cold weather.If frozen, pour warm (not boiling) water over the external pipe or apply a heat pad to thaw it.Reset the boiler once the pipe is clear to see if the error clears.
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