BoilerFaultCodesTechnical description
Burner overheat. Reset as described for code 01.
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety sensor to shut the system down to prevent damage. It is usually caused by a lack of water flow, which often happens if the internal pump has failed or if there is a severe blockage in the main heat exchanger. In some cases, the sensor itself may have developed a fault and is incorrectly reporting that the unit is overheating.
This issue often surfaces when the heating is first turned on after summer, as the internal pump can seize up during long periods of inactivity.
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.