combi-boiler + split aircon

[pj-italy]

Hi all - having trouble researching this issue. I have a Viessmann combi-boiler that sends hot water to my home’s radiators, and 4 x Hitachi splits with wifi adapters installed in each of them, to provide cooling (and supplementary heat if needed).  Can I connect both systems to my nest learning thermostat, so that I can just set the house to a desired temperature and the thermostat will use the combi-boiler or the splits, as needed?  The heat link is connected to the combi-boiler.

Thanks for any advice!

[AlexD · Accepted solution]

Thank you for your question @pj-italy . I would be happy to try and assist. The EU version of the Google Nest thermostat is able to control heating systems only, and hot water for the 3rd generation version.

It does not have the option or connectors to interface with other types of systems. So air conditioners, reversible or hybrid heat pumps are not something it can control. 

It is only able to control 1 system. That is why you need 1 thermostat for each heating zone if you have multiple zone valves at the location.