2-Wire, 230VAC Compatible?

[FrankL25]

I am looking to install a Nest 3rd Generation thermostat and have a couple of questions.  

My current thermostat has two wires from my combi boiler.  The thermostat is switching 230 VAC.  The thermostat is powered by two AA batteries.  

First question - can the Nest safely switch 230 VAC?  

Second question - do I need to supply 24 VAC or 24 VDC to the Nest and, if so, to which terminals will the 24 volts be connected?

[CoolingWizard]

Unfortunately no. the Nest thermostats are only compatible with HVAC equipment that use a 24 Volt AC power. 

AC Cooling Wizard 

[FrankL25 · Accepted solution]

So....I'm going to reply to my own question, just in case someone has the same or similar question.

Firstly, I decided to contact Google Nest Support and was very pleased with the level of support and the information I received.

Secondly, the answer to all my questions was in learning about the Nest Heat Link.  I've used Nest thermostats previously in the US and the Heat Link is not required there, as the HVAC systems there use low voltage (24v).

Thirdly - the answer to my first question is kind of both yes and no.  The Thermostat Display (Note: It is called a Thermostat DISPLAY.  Which should have been a clue.)  can not switch 230VAC, but the Heat Link can.  Basically, as I understand it, the Heat Link has the switching relay and a 12VDC power supply for the Thermostat Display.  The inclusion of the 12VDC power supply answers my second question.

All that just goes to show that you can learn something new every day.

[Jenelyn_O]

Hi there

Thanks for reaching out and for posting all the information that will be helpful to other users of the Community. If you have any questions or concerns, please let us know so we can further assist you. Otherwise, I'll be locking this thread after 24 hours. 

I appreciate your help, @CoolingWizard.

Best,
Jenelyn

[Dan_A]

Hey there,

I wanted to follow up and see if you still need help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,

Dan

[Dan_A]

Hey there FrankL25,

We haven't heard from you in a while so we'll be locking this thread if there is no update within 24 hours. If you need assistance or want to discuss topics, feel free to start a new thread.

Cheers,

Dan