BoilerFaultCodesIntergas 23 Fault Code
The Intergas 23 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 10 Intergas models in our database.
Technical description: Sensor fault S2
What causes the Intergas 23 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.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Intergas models that show the 23 fault code
Click a model for the full fault code list and model-specific repair notes.
- Combi Compact Eco RF Repair: £90-180
- Combi Compact HRE 24/18 Repair: £90-180
- Combi Compact HRE 28/24 Repair: £90-180
- Combi Compact HRE 36/30 Repair: £90-180
- Combi Compact HRE OV Repair: £90-180
- Combi Compact HRE SB Repair: £90-180
- Compact HRE OV Repair: £120-190
- Rapid 25 Repair: £90-180
- Rapid 25 32 Repair: £90-180
- Rapid 32 Repair: £90-180
Source
Intergas 23 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