cancel
Showing results for 
Search instead for 
Did you mean: 
Replies are disabled for this topic. Start a new one or visit our Help Center.

Nest with multiple zone

fmoacc
Community Member

I'm looking to replace four older dial thermostats with smart thermostats. We have four areas of zone hydronic heating. I'm probably going to have them installed but I need to make sure I'm getting the right hardware. When doing zone heating can a single Nest Thermostat unit control the zones if you have Nest Temperature Sensors at the other zone locations or does each hub need a full Nest Thermostat? All of the current thermostats have just R and W wires so for most models it seems I'll need to hook the nest power wire (cwire replacement thing) in as well. From what I seems one at the base should be able to support all four mounts? Lots of questions I know I just want to make sure I buy the right equipment.

2 REPLIES 2

AidyBee
Community Member

Researching like you but my understanding is one nest thermostat and heatsink per zone. Max of 20 zones per home. I think the temperature senders are more about getting a range of readings from various points around a larger zone so the thermostat can make a more informed decision bead on the average across the whole of the zone.

Info in the Nest support sites / manuals suggest that multi zone control you should wire the heatlink to the corresponding zone valve,  not the boiler. Nest controls the valve; the valve controls the boiler.

For me, the only thing that isn't clear is now to neatly control HW in a coordinated and coherent way in a multi zone installation. Ideally, I'd like to synchronise / pair the HW channel on all zone nests so that you can adjust a single HW channel from any of the zone thermostats - like a genuinely integrated system. However, I'm not sure that is possible as most people talk about picking a zone to control HW and omit it from all other zone controllers which is a bit naff...

Anyway, hope that helps and happy to be corrected if you find any different information...

laurentbourg
Bronze
Bronze

You cannot control a 4 zone hydronic system with 1 Nest. Each thermostat is connected to a central controller, typically a Taco 4 zone control module which does the valve switching and aquastat control. 

So you need one Nest thermostat to replace each dial thermostat. You should not need a C wire, most of the time Nest thermostats are able to “steal” power out of the R line.

Suggest you purchase one Nest learning thermostat and replace one of the dials and then if it all works well you can go ahead and replace all the remaining ones.