BoilerFaultCodesYour boiler is having trouble communicating with the internal clock or plug-in timer, preventing it from knowing when to turn on.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Programmer input
What causes this fault?
This fault happens when the boiler's main control board loses touch with the plug-in timer or external programmer responsible for scheduling your heating. It is usually caused by a loose connection in the internal wiring or a mechanical failure within the clock component itself, meaning the boiler doesn't receive the 'on' signal it expects. While the boiler's hardware might be fine, it stays idle because it can no longer see your heating schedule.
DIY fix possible
Check that the plug-in timer or programmer is firmly pushed into the boiler fasciaReset the boiler by holding the reset button for five secondsEnsure any external room thermostats have fresh batteries and are calling for heat
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A boiler cover plan would cover faults like 6.E — no call-out fees, no surprises.
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Could it be time for a new boiler?
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