BoilerFaultCodesYour boiler has shut down because the electricity supply reaching it is too low for it to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Low power supply lockout
What causes this fault?
This fault occurs when the electrical voltage entering the boiler drops below the level required for the internal components to function reliably. The most common reason is an issue with your home’s main electrical supply or faulty wiring leading to the unit, though it can also be caused by a failing control board that can no longer process power correctly. The boiler shuts down as a safety precaution to prevent damage to the sensitive electronic motors and valves.
This fault is occasionally more common during peak winter months when the national grid or local substations are under heavy load, leading to 'brownouts' or temporary drops in voltage.
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 E34 — 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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