BoilerFaultCodesIntergas F016 Fault Code
The Intergas F016 fault code means: your boiler has detected an internal communication error or a connection issue with a sensor that monitors the main heat exchanger.. It appears on 5 Intergas models in our database.
Technical description: Mounting fault S3
What causes the Intergas F016 fault?
This fault occurs when the boiler's control board loses signal or receives an unexpected reading from the sensor mounted on the main heat exchanger. The most common reason is a loose or damaged connection in the internal wiring, or the sensor itself has developed an electrical fault and can no longer report data correctly. In some cases, it can also indicate that the main circuit board is failing to process the signals it receives from the safety components.
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 F016 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Intergas F016 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