BoilerFaultCodesYour boiler has shut down because it is unable to drain away the waste water it produces, or a safety sensor on the flue system has been triggered.
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 or feedback of accessorie blocks heating | condensate pump defective or flume flap feedback triggered
What causes this fault?
This fault occurs when the boiler's internal safety system detects that waste water cannot properly exit the unit, or a mechanical flap in the flue pipe has failed to open. The most common cause is a blockage or electrical failure in an external condensate pump that is responsible for carrying away excess liquid. It can also be triggered if the flue system is obstructed, preventing the boiler from safely exhausting its gases.
This fault is frequently seen during freezing winter spells, as the external drain pipes can freeze solid, causing water to back up into the pump or boiler.
DIY fix possible
Check if the external condensate pipe is frozen during cold weather and thaw with warm water if necessary.Ensure any external drain pipes are not blocked by debris or leaves.If you have an external condensate pump, check that it is plugged in and the power is turned on.Press the reset button (flame symbol) once to see if the fault clears.
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