BoilerFaultCodesYour boiler has stopped working because it cannot communicate with its internal memory chip or the main control board is malfunctioning.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Burner blocked - Boiler coding card missing, faulty or incorrect card inserted
What causes this fault?
This fault occurs when the boiler's main brain loses its connection with the internal memory chip that tells it how to operate. The most common reason is that this small coding card has become loose, developed a hardware fault, or the main control board itself has suffered an electrical failure and can no longer read the data.
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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