BoilerFaultCodesYour boiler's internal computer parts are struggling to talk to each other, which prevents the system from starting up normally.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Communication fault
What causes this fault?
This fault occurs when the boiler's main control board loses the ability to send or receive data from the display panel. The most common reason is a physical connection failure, such as loose wiring or moisture damage to the sensitive circuit boards, which prevents the system from confirming it is safe to fire up.
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 20 — no call-out fees, no surprises.
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