Medium Warning
4 12 on Ariston Challenger 80E

Your boiler is having trouble communicating with the temperature sensor for your secondary heating zone, meaning it doesn't know how warm that specific part of your home is.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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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 ZONA 2

What causes this fault?

This fault occurs when the boiler's control board can no longer read temperature data from the thermostat or sensor dedicated to the second heating area of your home. The most common reason is a loose electrical connection, a broken wire, or a failure within the sensor itself that prevents it from sending a signal.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

4 11View →4 13View →

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