BoilerFaultCodesYour boiler's internal computer has encountered a fault and is unable to communicate with the rest of the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Printed circuit board (PCB) error
What causes this fault?
This fault occurs when the boiler's main control board suffers an internal electronic failure or loses its programmed memory. The most common reason is age-related component wear, though sudden electrical surges or moisture getting onto the circuitry can also cause the board to stop functioning correctly.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 303 — 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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