Low
C1 05 on Atag Sov.

Your boiler is currently running an automatic cycle to clear trapped air from the system, which typically occurs after it has been powered on or refilled.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

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

Venting program active

DIY fix possible

Wait approximately 7 to 10 minutes for the automatic cycle to finishEnsure all radiator valves are open to help move air through the systemCheck the system pressure gauge and top up to 1.5 bar if it has dropped

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Related fault codes

C1 10View →C1 18View →

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