Your boiler's internal computer brain is having trouble reading its memory, which prevents the system from starting up safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: EEPROM error
What causes this fault?
This fault occurs when the boiler's main control board experiences a data processing failure, meaning it can no longer access the essential instructions needed to run the system. It is usually caused by a hardware malfunction within the circuitry or an internal memory corruption that prevents the boiler from completing its safety checks. Because the 'brain' of the boiler cannot verify how to operate safely, it shuts down entirely to prevent any unpredictable behavior.
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.63 — 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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