BoilerFaultCodesWhat the manual says
Manufacturer manualFault: Invalid Device Specific Number - Incorrect/missing Device Specific Number or incorrect/missing coding resistor
Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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 is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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