BoilerFaultCodesIntergas 20 Fault Code
The Intergas 20 fault code means: your boiler has detected a problem with the temperature sensor that monitors the water returning to the unit, causing it to stop running for safety.. It appears on 7 Intergas models in our database.
Technical description: Sensor fault S2
What causes the Intergas 20 fault?
This fault occurs when the boiler's internal computer stops receiving a reliable temperature reading from the sensor on the return pipe. It is usually caused by the sensor itself failing, or a loose connection in the wiring that prevents the signal from reaching the control board. For safety, the boiler shuts down because it can no longer monitor if the water returning from your radiators is at a safe temperature.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Intergas models that show the 20 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Intergas 20 fault code information on this page is sourced and cross-checked against the official Intergas service / installation manuals for each affected model.
- Intergas Combi Compact ECO RF manual (PDF)
- Intergas Combi Compact HRE 36/30 manual (PDF)
- Intergas Compact HRE OV manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026