BoilerFaultCodesGrant PP3 Fault Code
The Grant PP3 fault code means: your boiler has stopped working because an internal sensor that monitors the temperature of the heating coil is no longer sending a correct reading.. It appears on 2 Grant models in our database.
Technical description: Coil temperature sensor failure
What causes the Grant PP3 fault?
This fault occurs when the boiler's control board loses communication with the sensor monitoring the internal heating coil. The most common reason is that the sensor has developed an internal electrical failure or the wiring connecting it to the main board has become loose or damaged over time.
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 PP3 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant PP3 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