BoilerFaultCodesYour boiler's internal computer has become confused by its own settings and can no longer communicate correctly with 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: Card parameter error – possibly wrong card parameter setting
What causes this fault?
This fault occurs when the boiler's main control board loses its configured identity or has been programmed with the wrong software instructions. It is usually caused by a sudden electrical surge, a component failure on the circuit board, or the installation of a replacement part that hasn't been properly matched to your specific boiler model.
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 A23 — 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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