# Wi-Fi enabled thermostats **URL:** \ **Category:** Factual Questions\ **Created:** [December 15, 2023, 8:57pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653 "2023-12-15T20:57:57Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Fir\_na\_tine](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@Fir\_na\_tine](https://boards.straightdope.com/u/Fir_na_tine)\ **Post date:** [December 15, 2023, 8:57pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/1 "2023-12-15T20:57:57Z")
Looking to install a wi-fi enabled thermostat so I can adjust temperature when we’re traveling. My current t-stats are dumb 2 wire jobs. The t-stat either calls for heat or it doesn’t. In looking at ads for the wi-fi version they all require a C wire. Which appears to me to be the power to the T-stat so it maintains a wi-fi connection. But they also seem to require a tie in to the boiler control panel. Has anyone found one with a simple 12VDC transformer like a old fashioned doorbell unit? Don’t really want to screw around with the boiler control panel if I don’t need to. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [December 15, 2023, 9:32pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/2 "2023-12-15T21:32:00Z")
They generally run on 24VAC, not 12VDC. None of the thermostats are going to care if they’re getting 24VAC from the boiler control panel vs a separate transformer. However, all of the thermostats I’m aware of are using the unswitched side of the 24VAC relay that the thermostat closes to call for heating/cooling to power the thermostat. This means if you hook up a separate transformer you’d be sending the transformer’s 24V into the boiler control panel instead of the panel’s own 24V, and the boiler control panel might care about that. ---
**Author:** ![Fir\_na\_tine](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@Fir\_na\_tine](https://boards.straightdope.com/u/Fir_na_tine)\ **Post date:** [December 15, 2023, 10:25pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/3 "2023-12-15T22:25:55Z")
So if I take a multi-meter and find the 24 volt tap on my zone control panel, I can use that to run a wire to a wi-fi T-stat? ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [December 15, 2023, 10:35pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/4 "2023-12-15T22:35:39Z")
You already have a 24V tap running from the control panel to your thermostat. Your thermostat switches that 24V to the ‘call for heat’ terminal on the control panel. What you need is a common (ground) wire so that you have a power circuit to run the fancy-pants thermostat. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [December 15, 2023, 11:08pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/5 "2023-12-15T23:08:46Z")
> [@Gorsnak](#): > > common (ground) wire Which is the “C” wire you’re reading about, @Fir_na_tine. > **[Thermostat C-Wire: How it Works on Your Thermostat | Honeywell Home](https://www.honeywellhome.com/us/en/support/everything-you-need-to-know-about-a-c-wire/)** > > What is a c-wire? Everything you need to know about a c-wire can be found in the Honeywell Home Support and Resources Center. ---
**Author:** ![Dereknocue67](https://avatars.discourse-cdn.com/v4/letter/d/6de8d8/32.png) [@Dereknocue67](https://boards.straightdope.com/u/Dereknocue67)\ **Post date:** [December 16, 2023, 9:04am UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/6 "2023-12-16T09:04:49Z")
I have a wifi Sensi thermostat requiring no C wire. Works great with the app. [https://www.amazon.com/Emerson-Thermostat-Version-Energy-Certified/dp/B01NB1OB0I/ref=sr\_1\_5?crid=25C3MK94K3Y6E&keywords=sensi%2Bthermostat&qid=1702717403&sprefix=sensi%2Caps%2C167&sr=8-5&th=1](https://www.amazon.com/Emerson-Thermostat-Version-Energy-Certified/dp/B01NB1OB0I/ref=sr_1_5?crid=25C3MK94K3Y6E&keywords=sensi%2Bthermostat&qid=1702717403&sprefix=sensi%2Caps%2C167&sr=8-5&th=1) ---
**Author:** ![Paintcharge](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paintcharge/32/7946_2.png) [@Paintcharge](https://boards.straightdope.com/u/Paintcharge)\ **Post date:** [December 16, 2023, 8:26pm UTC](https://boards.straightdope.com/t/wi-fi-enabled-thermostats/994653/7 "2023-12-16T20:26:02Z")
My Nest only has 2 wires. They plug into W1 and Rh. I replaced a dumb thermometer with the Nest. Simple swap. Love being able to use the app from work and make it warm when I get home.