Medium Warning
52:0 on Viessmann Vitodens 200-W

Your boiler is struggling to monitor the temperature of a specific part of your system's pipework, which may cause your heating to run less efficiently or stop working correctly.

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

Without flow temperature sensor for low loss header

What causes this fault?

This fault occurs when the boiler loses communication with the sensor responsible for tracking water temperature in the main mixing chamber of your plumbing. The most common reason is that the sensor itself has failed internally or the wiring connecting it to the boiler's main control board has become loose or damaged. Without this data, the boiler cannot accurately balance the heat output for your home.

Engineer required

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

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