BoilerFaultCodesYour boiler's main control board has lost its identity or is communicating incorrectly with the display unit, often following a part replacement.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault: Invalid Device Specific Number - Incorrect/missing Device Specific Number or incorrect/missing coding resistor
What causes this fault?
This fault occurs when the boiler's internal computer chips fail to recognize each other, essentially causing an identity crisis within the system. It most commonly happens after a new control board or display has been installed but hasn't been properly programmed with the specific code that matches your exact boiler model.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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