BoilerFaultCodesWhat the manual says
Manufacturer manualSoftware incompatibility.
From this model's manual
Verified against the Glow Worm Xtramax He installation & service manual, page 33.
What causes this fault?
This fault occurs when the main control board and the display panel are unable to talk to each other correctly because their internal programs do not match. This usually happens after a repair where a new part has been installed that is running a different software version than the original components. It essentially means the boiler’s 'brain' and its 'voice' are no longer speaking the same language.
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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