Low
C123 on Atag E22c

Your boiler is displaying a request for a security password to enter the technical settings menu, which is intended for professional engineers only.

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.

What the manual says

Manufacturer manual

Access code for installer level (to access PARA, INFO, SERV, and ERRO chapters).

From this model's manual
Verified against the Atag E22c Combi installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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