BoilerFaultCodesTechnical description
Ion base value exceeds the upper factory limit – try resetting the boiler
What causes this fault?
This fault occurs when the boiler's internal sensors detect an electrical current that is too high or unstable during the combustion process. It is often caused by a buildup of carbon on the flame-sensing probe or a fault in the wiring that prevents the control board from accurately monitoring the burner. As a safety measure, the boiler shuts down because it cannot be certain that the flame is burning correctly or safely.
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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