BoilerFaultCodesYour boiler is struggling to send signals between its internal components because the communication line has a low electrical voltage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault: eBUS - Undervoltage on the eBUS
What causes this fault?
This fault occurs when the boiler's internal communication system experiences a power drop that prevents components from 'talking' to each other. The most common reason is an electrical short circuit in the wiring or a failing electronic control board that can no longer maintain the correct voltage. It can also be triggered if external smart controls or thermostats are incorrectly wired into the boiler's data port.
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 F.49 — 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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