BoilerFaultCodesYour boiler is performing a routine automatic cleaning and filling cycle of its internal drainage system, which is a normal process and not actually a fault.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Syphon-fill programme
What causes this fault?
This code appears because the boiler is automatically filling its internal 'trap' with water to ensure harmful flue gases cannot escape into your home. It typically occurs after the boiler has been powered off and back on, or if the unit has been sitting idle for a long period. The system is simply performing a safety check and preparation cycle before the burner ignites.
This is more common in summer or after a holiday when the heating has been switched off for several days, triggering the automatic refill when it is finally turned back on.
DIY fix possible
Wait approximately 15 to 20 minutes for the cycle to complete automatically.Do not cycle the power or reset the boiler during this time.The boiler will return to normal operation and heat the home once the cycle finishes.
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