Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I found a question regarding the Nest thermostat here. But that is only a question "Will it work?". Thanks to that I know it WILL, the problem is...HOW. I know the wire naming conventions are different etc, and also that there is a "OpenTherm" protocol over which thermostat and boiler are communicating.

I found a way how to supply the Nest thermostat with separate transformator power supply(24V) and I hooked up a relay on heating and it simply does not work. My question is, can Nest do this and if so, how should I connect it in order to make it work?

share|improve this question
What wires wires do you have now (colors and/or labels)? What terminals do they go into on your existing thermostat? I just happened to read an article recently that covers how to get NEST set up in Europe and also how to hack NEST to show correct location. Note that this is NOT a supported config, and the guy is using network hacks to trick the NEST to act how he wants. Help with the network/software part is beyond scope of this site. – gregmac Oct 9 '12 at 2:00
That is a great article, however, I connected nest directly to boiler where it should operate with relay and I am not sure whether Nest copes with that or it has to have some standard protocol, such as OpenTherm...? – Michal Oct 9 '12 at 7:50
This is a question for the manufacturer. Brand specific advice is off topic here. See the faq. – The Evil Greebo Dec 12 '12 at 12:30
I found three other questions regarding Nest. None of them is closed for being off-topic. I didn't think about looking in faq two months ago since none of them had been closed. – Michal Dec 12 '12 at 12:36

Check out my blog,

Humble, just trying to share my experience implementing nest on a 220 240 v system


share|improve this answer
-1. Answers that rely on a link don't work well on SE, since links can go bad over time. Please make sure the post here answers the question and only uses links for added detail. See the faq for more information. – BMitch Jan 13 '13 at 22:41
See also the section on self promotion – ChrisF Jan 13 '13 at 23:04

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.