BoilerFaultCodesYour boiler's internal computer chips are unable to communicate properly due to a software version mismatch.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: MMI software incompatible with IRIS software
What causes this fault?
This fault occurs when the boiler's internal control boards are running different versions of software that cannot speak to each other. It most commonly happens after a repair where a new part has been installed that is not programmed to match the existing chips, or if a power surge has corrupted the board's memory. Because the different components cannot coordinate safely, the boiler shuts down as a precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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