How to Program a CT50 Thermostat

This article primarily exists to make available a small spreadsheet calculator that I created to help you program your Radio Thermostat brand CT50 (and probably CT80 though I haven't tested it) Thermostat (when it is connected to a wireless network via their wireless module).

The CT50 thermostat's programming can be set using the thermostat itself, but the interface is clunky and slow. When connected to a wireless network, you can quickly program the thermostat using HTTP requests (based on their HTTP API File:Radio Thermostat CT50 API RTCOAWiFIAPIV1 3.pdf).

You can send HTTP requests from a command line very easily using a utility called curl. It is available in most Linux distros and can be installed by typing something like sudo apt install curl or sudo yum install curl. There are also downloads for 32- & 64- bit Windows.

Now to the secret sauce of this article. Here is a download for an ODS spreadsheet that will have you quickly and easily create these curl commands File:CT50 curl maker.ods.


  1. Install curl
  2. Download the file File:CT50 curl maker.ods
  3. Open it in LibreOffice Calc, OpenOffice Calc, or Microsoft Excel
  4. Enter your thermostat hostname (or IP address) and desired settings into the orange boxes
  5. Copy the text from the grey boxes (either one day at a time or the All Days cell to set the entire week at once)
  6. Paste the text into yout terminal or command line program and hit enter!

Here is an example screenshot from the calculator