Medium
E33 on Chaffoteaux Minima HE

Your boiler has detected that the external temperature sensor for your underfloor heating system is not sending a signal, which is preventing the boiler from firing.

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

Floor heating thermostat open circuit (if fitted)

Engineer required

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

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