BoilerFaultCodesTechnical description
Boiler overheat – check that any valves to the heating circuit have not been shut down, no air in the system and that the water pressure is correct
What causes this fault?
This fault occurs when the water inside the heat exchanger reaches a dangerously high temperature, triggering a safety sensor to cut the power. The most common reasons are a lack of water flow caused by a failed pump, a blockage in the pipework, or air trapped within the system preventing heat from being moved away from the burner.
This issue often appears when the heating is first turned on after summer, as internal pump components 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.