BoilerFaultCodesAtag 80 Fault Code
The Atag 80 fault code means: your boiler has automatically turned itself off because the exhaust gases getting rid of waste fumes are becoming too hot, suggesting a potential blockage or efficiency issue.. It appears on 6 Atag models in our database.
Technical description: Maximum flue gas temperature has been exceeded (if present). The block will not be cancelled until the flue gas temperature has lowered to a correct figure.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Atag models that show the 80 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Atag 80 fault code information on this page is sourced and cross-checked against the official Atag service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026