BoilerFaultCodesTechnical description
Internal fault (locked-out)
What causes this fault?
This fault occurs when the boiler’s control board detects a safety issue or a failure to ignite, leading it to shut down the system for protection. The most common reasons include a worn ignition electrode that can no longer spark correctly or an internal electrical failure within the main circuit board. In some cases, a faulty sensor may be sending incorrect temperature readings, causing the boiler to trip its safety limit.
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.
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