Radio thermostat CT101- help for former Iris user


New to SmartThings, former IRIS user, and I’m trying to pair my Radio Thermostat CT101. It seems to be the only thermostat out there that doesn’t require a c wire for my gas thermostat. It worked perfectly with IRIS and I’ve been looking everywhere for compatibility with SmartThings. Anyone know of an easy solution that I wouldn’t have to purchase any additional modules? Or maybe a newer one battery operated that may work.

Thanks in advance!

I have a CT100 and installed a CT101 at my Dad’s house a few weeks ago, and we both have SmartThings hubs. The CT101 will work just like the CT100, and will use the same device handler. Try looking up CT100 documentation for pairing instructions. I can’t recall the pairing steps, but it’s the same as the CT100.

Edit: You might also try a factory reset if your having trouble. Remember to adjust the HVAC setup before pairing. Here’s a link to a doc I found… See page 10 for details on that.

Another edit:
Here’s a link to the RadoThermostat CT100 install doc. Page 20 explains how to get into pairing mode.


It worked!! I did a few things and looked up the CT100. I didn’t even get to see what you last attached.

You just saved us lots of aggravation and time! So appreciate it! :grin:

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Glad it worked!

I lacked a c-wire when I installed our CT100, but I lucked out and found a connection on the HVAC unit and had a spare wire already run I could use. Before that I was looking at alternatives and found c-wire adaptors. It’s basically a wall-wart that provides power if you don’t have a c-wire. I think I saw them on Amazon.

If your looking for a good scheduler, check out rboys Weekday/Weekend (5-2 day) smart app. It works beautifully for my thermostat. If you search around this forum you can find more information, or check out their site. It requires a little effort to install, but they have instructions and it’s not difficult.

Excellent info. Thank you for your time! I’m excited to see more possibilities and ways I can explore new features :grin: