BoilerFaultCodesAtag 140 Fault Code
The Atag 140 fault code means: your boiler has stopped working because it cannot detect the water pump running or there is a lack of water circulation to maintain safe operation.. It appears on 2 Atag models in our database.
Technical description: Dynamic Pressure Check Failed (or no pump detection)
DIY fix possible
Check the pressure gauge is between 1.0 and 1.5 bar; top up using the filling loop if it is too low.Ensure all radiator valves and boiler isolation valves are fully open.Try resetting the boiler by pressing the 'Reset' button once the pressure is corrected.
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Atag models that show the 140 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Atag 140 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