BoilerFaultCodesYour boiler has lost communication with the main thermostat or temperature sensor that controls your primary heating zone.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: Room sensor circuit open or short circuit zone 1
What causes this fault?
This fault occurs when the connection between your boiler's internal computer and the main room thermostat is broken. The most common reason is a loose or damaged wire within the control circuit, or a component failure inside the thermostat itself that prevents it from sending signals to the boiler.
DIY fix possible
Check if your room thermostat or Clima Manager has run out of batteriesEnsure all wired connections to the thermostat are secure and haven't been knockedRestart the boiler using the Reset button to see if the communication error clears
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A boiler cover plan would cover faults like 411 — no call-out fees, no surprises.
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