2 heating zones + Hot water, and 2 Thermostats and OpenTherm

[Dave_UK_CB24]

Hi,

I have a 2 heating zones + Hot water, and 2  currently normal thermostats, I have seen posts/ Nest website info indicating I can control 2 zones by adding additional Nest thermostats, okay makes sense so far. I will buy a new boiler that supports OpenTherm, so I want to use it, the question is there is a single OT communication link with the boiler, how can  each zone / heat link communicate it's heat demand vie OT?

My thoughts are it can't , a 2 zone stem has to work vie on /off wiring, which defeats the objective.

Regards

David 

[DragosC]

Hi there @Dave_UK_CB24,

Thanks for letting me know. Let me see if I got the situation straight, you'd like to use the OpenTherm module from the Nest Thermostat for 2 zones? The zoned heating is not compatible with the OpenTherm module from the Nest Thermostat's Heat Link. And even if you purchase a module to split it between the zones, it will not be able to control them separately. 

Should you need any more help, please let me know. 

[Dave_UK_CB24]

Hi, yes I want to control 2 zones, the new boiler is compatible to Nest heatlink OT, the fundamental problem is how do 2 X heatlinks , 1 for each zone, connect vie OT to one boiler.

[DragosC]

The zoned heating is not compatible with the OpenThem, it can be used on one zone only. 

[Dave_UK_CB24]

Thanks that was also my conclusion, to work  the 2 thermostats would have to work in  a master slave relationship , the master talks to boiler, and slave thermostat to the master thermostat, add the use case to your development roadmap...

[AndaD]

That's a good perspective of seeing things, and yes you're right. Well, hopefully to find the best way to have a setup that will help you with the zoned heating. Is there anything else I can assist you with at the moment? 

[Dave_UK_CB24]

No, thank for your prompt replies.

[AndaD]

You're most welcome, it's been our pleasure. Be well and stay safe!