BoilerFaultCodesYour boiler has encountered an internal communication error between its main control boards, causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: BMM error
What causes this fault?
This fault occurs when the boiler's internal computer chips lose the ability to speak to one another, preventing the system from confirming it is safe to fire. The most common reason is a technical glitch or a physical failure within the main control boards or the wiring that connects them. Think of it like a lost connection between a computer and its screen that forces the whole system to freeze for safety.
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 F019 — 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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