BoilerFaultCodesYour boiler's main control unit is confused because a specific internal configuration component is missing or has the wrong electrical profile.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Coded resistance fault
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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like F43 — no call-out fees, no surprises.
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