Medium
LED 6 yellow (0) [DHW mode] on Ferroli Optima 201

Your boiler is struggling to detect the temperature of your hot water because of a faulty connection or sensor, which means it will likely stop providing hot water until fixed.

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

Short circuit on D.H.W. sensor (42) or resistance lower than 500 Ohm

Engineer required

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

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