BoilerFaultCodesTechnical description
The ionisation current detected by the system during the burning phase was insufficient
What causes this fault?
This fault occurs when the boiler successfully lights but cannot confirm that the flame is staying lit, causing the system to shut down for safety. The most common reasons are a worn-out sensor that can no longer 'see' the flame, a build-up of carbon on the internal components, or a slight fluctuation in the gas supply that prevents a steady burn.
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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