Medium Warning
A0:1 on Viessmann Vitodens 050-W

Your boiler has lost communication with its remote control thermostat, meaning it cannot receive temperature instructions.

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

With Vitotrol 200 (automatic recognition)

What causes this fault?

This fault occurs when the link between your boiler and its wall-mounted control unit is broken. The most common reasons are a loose wiring connection at either end, damage to the communication cable, or a internal glitch in the control unit's electronic circuit board.

DIY fix possible

Check that the Vitotrol remote unit is properly docked in its wall base.Inspect the wiring between the remote and the boiler for any loose connections or damage.Restart the boiler to trigger a new automatic recognition scan.

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