BoilerFaultCodesYour boiler is struggling to control its power level correctly, which may lead to it shutting down to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Actual burner modulation: Actual burner modulation.
What causes this fault?
This fault occurs when the boiler's internal computer is unable to accurately communicate with the gas valve to throttle the flame up or down. It typically happens because the electronic signals sent to regulate the fuel flow are being interrupted or misinterpreted by a failing control board. Without the ability to precisely control its power level, the boiler shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 1-b8 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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