BoilerFaultCodesTechnical description
No or insufficient ionisation flow.
What causes this fault?
This fault occurs when the boiler's internal sensor fails to detect a steady flame during the start-up sequence, forcing the system to shut down for safety. The most common reasons are a worn-out sensor probe that can no longer 'see' the flame, a faulty ignition cable, or an issue with the gas valve not delivering the correct amount of fuel.
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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