BoilerFaultCodesTechnical description
The boiler has failed to ignite or has overheated, when this happens the boiler automatically shuts down and requires to be reset manually.
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water temperature has exceeded a safe limit or the flame failed to light after several attempts. Often, this is caused by a lack of water flow through the heat exchanger, perhaps due to a failing pump or an airlock, triggering the safety shut-off to prevent internal damage. It can also be caused by a build-up of debris or a fault with the ignition system preventing a stable flame.
This issue is more frequent in winter when the heating system is under maximum load, which can highlight existing circulation problems or pump fatigue.
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.