Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: How do you wire this to a WiFi thermostat?  Which wires go where?
Document: Comes with no instructions whatsoever as to how to wire it into your device. Was recommended by Amazon for use with a Digital Thermostat requiring 24 Volt AC so how do you connect the wires, do you use one wire or two wires and where do they hook to the Thermostat ?
worked perfectly. I used to power my C wire for my wifi thermostat. Great price too! Home D***T price was $24 for the same thing!
I used this for a Radio Thermostat CT30 and it works perfectly. The cord is nice and long which allowed me to run it through the wall and basement with the other wires so it's completely hidden. It took less than 5 minutes. Sadly I spent way longer attempting to figure out if I had a C wire. I ordered this With my thermostat. I should have just used it from the start.
If you own the Filtrete (3M) Wifi Thermostat and you do NOT have a &#34;C&#34; wire hookup for power, this is what you need. Filtrete documentation will tell you that the thermostat will run on 12-24 volts, but anything less than 24 will not power the wifi card and the thermostat - the thermostat will turn on but the wifi will not work. Use this transformer and it works great.
So far so good. Using this to power a honeywell wifi thermostat I bought.So far all is working well.
This transformer did exactly what I needed. I needed to get power to my wireless thermostat (I don't have A/C, so no C wire) that was 24v. This did it.
I used this for a Honeywell wireless thermostat on a two-wire system that required 24 volts. It's a bit larger than I had hoped, but works well.
I needed to add a wireless thermostat to my house and the house wiring was only two wire. I needed an auxiliary power supply to power the thermostat and this worked perfectly.
One of my heating systems uses millivolt ignition which is not officially supported by a Nest learning thermostat as there is not enough supplied power to recharge and operate the thermostat. In my case, it is for a small LP stove that I wanted to monitor and control remotely. I simply installed the transformer and ran the wires to the common and the unused cooling control terminal on the Nest. It works perfectly and this thermostat always shows a higher battery charge level than my others.
Can use it on NEST, 3M or any of those new fancy WiFi thermostats on the market today :)
Answer: Following video may assist: http://www.youtube.com/watch?v=BgDseEF-4OY.I used the transformer to power a sprinkler control module and it worked fine.  I have no experience using it for the thermostat, but above URL may assist for providing the extermal power to the thermostat.