BoilerFaultCodesYour boiler has detected very low temperatures and is currently running to prevent internal components from freezing or is waiting for the system to warm up safely.
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: Pre heating exchanger / Frost protection
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water temperature has dropped to near-freezing levels, usually around 7°C. To protect itself from damage, the boiler automatically starts the pump and burner to circulate warm water until a safe internal temperature is reached. It can also be triggered if a temperature sensor is faulty and incorrectly reporting that the unit is freezing.
This code is most frequently seen during the winter months or during sudden overnight cold snaps when external temperatures drop significantly.
DIY fix possible
Check that your home heating is turned on to help circulate warm waterEnsure any exposed external pipes (condensate pipe) are not frozen or blockedWait for the boiler to complete its cycle; the code should disappear once the internal temperature rises
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