BoilerFaultCodesWhat the manual says
Manufacturer manualCoded resistance fault
From this model's manual
Verified against the Glow Worm Flexicom 18sx installation & service manual, page 46.
What causes this fault?
This fault occurs when the boiler's main control board loses its identity because a small electronic component called a coding chip is loose, damaged, or missing. The chip tells the computer exactly which model of boiler it is controlling, and without this information, the system shuts down for safety. The most common reason is a component failure within the electrical circuit or a loose connection following a recent repair.
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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