BoilerFaultCodesPotterton 28 Fault Code
The Potterton 28 fault code means: your boiler's hot water sensor has stopped working correctly, which means you may have inconsistent or no hot water.. It appears on 5 Potterton models in our database.
Technical description: Fault on Hot Water Sensor
What causes the Potterton 28 fault?
This fault occurs when the domestic hot water sensor, which monitors the temperature of the water going to your taps, provides an incorrect or missing electrical signal to the main control board. The most common reason is that the internal sensor has degraded over time or developed a short circuit, preventing the boiler from knowing how hot the water actually is. In some cases, it can also be caused by loose or corroded wiring connections between the sensor and the boiler’s brain.
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 28 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton 28 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