BoilerFaultCodesTechnical description
Sensor fault
What causes this fault?
This fault occurs when the boiler's internal thermometers, known as NTC sensors, stop communicating accurate temperature data to the main control board. The most common reason is that the sensors have physically degraded over time or have become coated in internal system debris, meaning they can no longer tell the boiler if the water is hot or cold. As a safety precaution, the boiler stops firing because it cannot be sure it won't overheat.
This fault can be more noticeable in winter when the boiler is under high demand and internal components are expanding and contracting more frequently due to the heat.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.