BoilerFaultCodesPotterton E28 Fault Code
The Potterton E28 fault code means: your boiler has lost the ability to measure the temperature of your hot water, which usually means it will stop providing hot water or provide it at an inconsistent temperature.. It appears on 13 Potterton models in our database.
Technical description: Hot Water NTC Fault
What causes the Potterton E28 fault?
This fault occurs when the internal sensor responsible for monitoring your hot water temperature has failed or is sending a broken signal to the main control board. The most common reason is that the sensor has physically degraded over time or developed a short circuit, preventing the boiler from knowing how hot the water is. In some cases, the issue may simply be a loose or corroded wire connection between the sensor and the boiler's computer.
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 →Potterton models that show the E28 fault code
Click a model for the full fault code list and model-specific repair notes.
- Assure Combi / System Repair: £120-£190
- Gold Combi HE Repair: £100-£180
- Gold HE Repair: £100-180
- Powermax HE Repair: £250-450
- Promax Repair: £100-£180
- Promax 15/2 HE Plus Repair: £200-400
- Promax Combi HE Plus Repair: £250-£450
- Promax HE Repair: £120-£200
- Promax HE Store Repair: £90-160
- Promax System HE Plus Repair: £120-£210
- Suprima HE Repair: £120-220
- Titanium Repair: £150-£300
- Titanium Combi Repair: £150-300
Source
Potterton E28 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