BoilerFaultCodesIntergas F031 Fault Code
The Intergas F031 fault code means: your boiler has stopped working because one of its internal temperature sensors is providing an incorrect reading or has failed.. It appears on 5 Intergas models in our database.
Technical description: Sensor fault S1.
What causes the Intergas F031 fault?
This fault occurs when the boiler's main control board detects a broken electrical circuit or an incorrect signal coming from the flow temperature sensor. The most common reason is that the sensor itself has developed an internal fault, though it can also be triggered by loose or corroded wiring in the harness. Because the boiler can no longer accurately monitor the heat of the water leaving the unit, it shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Intergas models that show the F031 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Intergas F031 fault code information on this page is sourced and cross-checked against the official Intergas service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026