Before I blew up another Boiler Could you please check my Hive wiring?

[Neil Dune]

Could someone help me if this is the correct wiring diagram and explanation please?

Hive Single channel to Viessmann Vitodens 050w (2017) combi boiler

- can my boiler start without 240Volt mains connection, just the common line
( assuming 24volts?) and Heating On (Terminal 3) from the Hive?

I have attached the wiring diagram of my boiler as reference on the same picture.

Hopefully no 2nd boilers blowing up this time.. Thank you kindly…

Best,

Neil

 

[muggles]

Those are OpenTherm terminals, designed to take a data connection from a high efficiency OpenTherm thermostat. Do not connect your Hive to them. Preferably, chuck the Hive in the bin where it rightly belongs and buy an OpenTherm stat which will improve the efficiency of your boiler

 

[ianmcd]

You would be better using an OT stat but you can use your existing hive but DO NOT connect it to those terminals at the boiler as @muggles says they are open therm terminals and you might damage your boiler electronics, use the 24v switching terminals and do not make any links at the hive end

 

[RandomGrinch]

Theoretically, the OT protocol allows for a dead short of the OT terminals (as is the case with the brown wire connecting terminals 1&2 in the OPs pic) to be interpreted by the boiler as a call-to-heat; as long as volt free switching is used on the Hive, little damage is likely to be done to the boiler PCB.

However, it's really not a good idea to use these terminals, when other options are available, to avoid the risk of unusual behaviour from the boiler!

As has been said above, an OT stat would provide much tighter control of the boilers output, than an on/off stat like a Hive.