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 13 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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A cover plan would handle faults like 28: no call-out fees, no surprise bills.
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Potterton models that show the 28 fault code
Click a model for the full fault code list and model-specific repair notes.
- Apollo Repair: £150-250
- Assure Repair: £150-350
- Gold Combi HE Repair: £150-250
- Performa 24 Repair: £90-160
- Performa 24 Eco HE Repair: £90-160
- Performa 24i HE Repair: £120-220
- Performa 28i Repair: £90-160
- Performa 30 HE Repair: £90-160
- Promax Combi 28 HE Plus Repair: £250-£450
- Promax Combi HE Plus Repair: £250-£450
- Promax Ultra Combi ErP Repair: £150-250
- Suprima HE Repair: £120-200
- Titanium Combi Repair: £150-300
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 7 July 2026