BoilerFaultCodesTechnical description
The boiler is fitted with an additional safety device, which shuts down the boiler in the event of the system or the boiler overheating. If the device operates, the Boiler Safety Overheat neon will illuminate and the boiler will shut down.
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 failed pump stopping water from circulating or a build-up of sludge and debris blocking the internal pipework. It can also be caused by a faulty internal sensor incorrectly reading the temperature.
This issue often surfaces during the first cold spell of autumn when the heating is turned back on after being idle all summer, which can cause the pump to seize.
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.