BoilerFaultCodesGrant PP2 Fault Code
The Grant PP2 fault code means: your boiler has detected a problem with a sensor that monitors the temperature of the exhaust gases, and it has likely stopped working as a safety precaution.. It appears on 2 Grant models in our database.
Technical description: Discharge gas sensor failure
What causes the Grant PP2 fault?
This fault occurs when the boiler's internal computer loses communication with the sensor that measures the temperature of the exhaust gases. The most common reason is that the sensor has developed an electrical fault or the wiring connecting it to the main control board has become loose or damaged. To ensure the appliance doesn't overheat or become unsafe, the boiler will automatically stop firing until the part is replaced.
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 →Grant models that show the PP2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant PP2 fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026