Nest thermostat compatibility

[Danai]

Hi all,

I'm trying to figure out if my home is compatible with any of the nest thermostats. I'm in Europe (NL), and currently have a simple Honeywell model. I attached here a pic of my current wiring, maybe someone can let me know if that works with nest?

Thanks in advance

 

[dmendell]

yes, if you don't have A/C or a separate fan control , this is work and it will get charged from the wall.

[george_t]

Hi @Danai, thank you for your interest in our products. Can you tell me what kind of boiler you have?: System or Combi and also is it OpenTherm? From the photo you sent I see the OpenTherm logo. For more details about the compatibility of nest thermostats you can find in this link: https://goo.gle/3xk3l3F.

[dmendell]

Hi George,

This house is in a snow region.

I was trying to determine best practices on how to use a Nest Thermo in a VRBO type rental situation.  It is controlling an  electric Forced air furnace, with a people controlled Pellet stove to save energy.

In the past I have used 2 thermostats.  One that is a absolute low temperatures freeze unit that cannot be changed and one that is set to a higher temperature that is enabled by my alarm system when it is disarmed.

I was hoping to make this a bit more modern.  I think I am going to run the R wire through the alarm system relay, with a 220ohm resister around it so: 1) Nest stays charged and 2) It controls the Furnace when people disarm the alarm when the relay closes.

Is 220ohm 5 watt the right ohm value, its a 24v system. Don't want to trigger the Furnace, but do want to keep the nest charged.  I'll may also keep secondary freeze thermostat in place if I need to, bypassing the relay/resister setup because I have an extra wire for that.

ANY TIPS?

[AlexD]

Thank you for all the details @dmendell . Just to confirm, are you looking at the US version of the Google Nest thermostat, that is just the display and base compatible with low voltage US systems or the EU version, like @Danai, that has the Heat Link unit and the thermostat display and runs on high voltage?

[dmendell]

Yes, that is correct. (:-)