Medium
205 on Ariston Alteas One

Your boiler has lost the wireless or wired communication with its external temperature sensor, meaning it doesn't know how hard it needs to work to heat your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

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

E-combi oneE-System oneClas Net one CombiClas one Combi

DIY fix possible

Check if your outdoor sensor has any visible damage or loose wires.If the sensor is wireless, replace the batteries in the external unit.Reset the boiler by pressing the 'Reset' button on the front panel.

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Related fault codes

202View →204View →

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