BoilerFaultCodesTechnical description
Overheat - Normally associated with either poor or lack of primary water circulation. Wait for appliance to cool then re-set as described for code 01.
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, triggering a safety shutdown to prevent damage. The most common reason is that the internal pump has failed or is blocked, preventing the heat from being carried away to your radiators. It can also be caused by a build-up of limescale in the heat exchanger or air trapped within the system.
This fault is often seen at the start of autumn when the heating is turned back on after being off all summer, which can cause the internal 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.