Your boiler's internal electronic computer chip is either missing, loose, or incompatible with the unit's software.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Code plug number: Coding plug number.
What causes this fault?
This fault occurs when the boiler's control system cannot communicate with its 'identity chip,' which tells the unit its specific model and power settings. This usually happens if the chip has vibrated loose from its socket on the main circuit board or if the chip itself has suffered an internal electrical failure. In some cases, a power surge may have corrupted the memory or damaged the printed circuit board where the chip is housed.
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 1-E3 — 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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