Make the Nest Thermostat wireless


I moved to a new house and I would like to install my Nest thermostat. The issue is that I cannot run new cables from the HVAC system to my house. Hence, I'm exploring the possibility of a wireless solution between my Nest and the HVAC.

They are already some wireless thermostat solutions like this one.

The principles are very simple: you connect to the HVAC a receiver, install the thermostat in your house and the HVAC commands will be sent wirelessly.

I would like to do a similar system for my Nest. The concept would be the following:

  • Connect the current Nest thermostat to a Arduino board
  • The Nest will execute the various command signals as usual: Heating on or off
  • The Arduino product will read the commands sent by the Nest: it's a basic on/off contact with 2 wires.
  • Once received, the Arduino will send over wifi the commands to a similar Arduino control board connected to the HVAC system
  • The Arduino control board will receive the commands from wifi and will send the inputs to the HVAC system through the 2 wires

Do you think my idea is feasible? And if yes, do you know where I can find people willing to build it for me? I would of course pay for this!


Do you think my idea is feasible?

If the only thing you care about, that the Nest does, is turning the HVAC system on or off, then yes.

But, what about heating vs. cooling?

How is the HVAC system controlled now?

And if yes, do you know where I can find people willing to build it for me?

An XBee at the Nest and an XBee at the HVAC system are all that you need. Nothing really to build. Simply configure one XBee to talk to the other, and to read one digital pin. Configure the second XBee to listen to, and respond to, the first one, and to write to one digital pin.