BoilerFaultCodesTechnical description
OVERHEAT ERROR
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, triggering an emergency shutdown to prevent damage. It is usually caused by a lack of water flow, often due to a pump failure or a blockage within the pipework that prevents heat from being carried away from the unit. In some cases, a build-up of limescale or sludge acts as an insulator, causing the internal components to get too hot too quickly.
This fault is frequently seen at the start of autumn when heating systems are turned back on after a long summer break, as internal pump components may have seized from disuse.
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.