Low
C123 on Atag A200

Your boiler is displaying a service notification indicating that a technician is attempting to enter or has entered the password-protected installer settings menu.

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

Installer level access code

DIY fix possible

Press the 'Reset' or 'Back' button to return to the main displayMonitor the screen to see if the code clears and the heating continues as normalIf the code persists, restart the boiler using the power isolation switch

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