BoilerFaultCodesIntergas F015 Fault Code
The Intergas F015 fault code means: your boiler has stopped working because one of its internal heat sensors has come loose or is not sitting correctly against the pipework.. It appears on 5 Intergas models in our database.
Technical description: Mounting fault sensor S1
What causes the Intergas F015 fault?
This fault occurs when the main flow sensor, which monitors the temperature of the water leaving the boiler, loses physical contact with the internal pipework. The most common reason is that the Retaining clip has become loose or broken, preventing the sensor from getting an accurate reading and causing the boiler to shut down for safety. In some cases, it may also be caused by a faulty wiring connection between the sensor and the main control board.
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 F015 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Intergas F015 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