BoilerFaultCodesYour boiler has identified an internal sensor or communication error that is preventing it from running properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temporary fault code (Refer to section 7.10)
What causes this fault?
This fault occurs when the boiler's main control board loses reliable communication with its internal sensors or fails to read the temperature data correctly. The most common reason is an electronic glitch or a failing main circuit board that can no longer process signals from the thermistors. In some cases, it can also be triggered by a faulty sensor sending an unstable voltage back to the control centre.
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 81 — no call-out fees, no surprises.
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