BoilerFaultCodesYour boiler's main control computer and the front display screen have stopped talking to each other, meaning the unit cannot function.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Control unit fault. Communication error with the display.
What causes this fault?
This fault occurs when the internal communication link between the boiler's main brain and the front control panel is broken. It is usually caused by a loose internal connection cable, a short circuit on one of the circuit boards, or moisture ingress affecting the sensitive electronics.
DIY fix possible
Turn the boiler power off at the fused spur switch (the wall switch).Wait for 60 seconds.Turn the power back on and see if the display restarts normally.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like E12 — no call-out fees, no surprises.
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