Medium
E596 on Navien NCB

Your boiler has lost its connection to your digital thermostat, meaning it no longer knows when to turn on your heating.

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

Communication Error with Smart Room Controller

DIY fix possible

Turn off the boiler at the fused spur or power switch for 60 seconds.Check the wiring connections between the thermostat and the boiler for any loose wires.Replace the batteries in the thermostat unit if it is a wireless version.

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