BoilerFaultCodesTechnical description
Shut down the boiler in the event of the system, the boiler or the flue overheating.
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the pipework that restricts flow. In some cases, the safety sensor itself may have become faulty and is reporting a high temperature incorrectly.
This issue often appears 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.
Find a Gas Safe engineer
Search the official register →