Medium Warning
bd on Viessmann Vitodens 222-W

Your boiler has lost connection with the remote control unit that manages your second heating zone, meaning you cannot adjust the temperature for that specific area.

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

Control mode without remote control: Communication fault - Vitotrol remote control heating circuit M2

What causes this fault?

This fault occurs when the boiler's main control board loses its digital handshake with the remote thermostat managing your second heating zone. Most often, this is caused by a loose connection in the low-voltage wiring or a hardware failure within the Vitotrol unit itself.

DIY fix possible

Check if the Vitotrol remote unit is properly seated on its wall baseSwitch the boiler off at the fused spur, wait 30 seconds, and switch it back on to reset the connectionInspect the remote unit batteries (if applicable) or check for visible damage to the wiring leading to the unit

Find a Gas Safe engineer
Search the official register →

Related fault codes

Related guides you might find useful