Medium
d.71 on Vaillant Ecomax Condensing 600/800 series

Your boiler has detected that the system settings for your heating are outside of the normal range, typically indicating a configuration error or an issue with the control board sensing the setup.

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

Maximum target value for heating system (ecoMAX 800)

Engineer required

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

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Related fault codes

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