BoilerFaultCodesPotterton 29 Fault Code
The Potterton 29 fault code means: your boiler has detected a problem with the sensor that monitors the temperature of the water flowing through your radiators, which prevents the heating from running correctly.. It appears on 2 Potterton models in our database.
Technical description: Fault on Central Heating Sensor
What causes the Potterton 29 fault?
This fault occurs when the internal sensor responsible for tracking the temperature of your heating water becomes faulty or loses its connection. The most common reason is that the electrical resistance inside the sensor has drifted out of its normal range due to age or internal wear, meaning it can no longer send an accurate signal to the boiler's control board.
This fault is often noticed during the first cold spell of autumn when the heating system is switched back on after being idle all summer.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Potterton models that show the 29 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton 29 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026