CT-100 T-Stat Filter Replacement Lights


I see the CT-100 has a ‘change filter’ light on the lower left side. There’s also 3 dots in a column above that look like they light up. I’ve checked the installation and user manuals and can’t find any reference to these.

Are they operational on this piece?

Must be a mystery. Either that or because I don’t have a C-wire. Anybody got one hooked to a C-wire that has a working light?

Here is a direct response from Radio Thermostat regarding those indicators. I have never actually seen one light up myself.

Here are the reasons: (Yellow Light Events)

When the power is restored after an outage and the thermostat detects battery power only.
When you push the reset button and the thermostat detects battery power only.
When the thermostat detects that the C wire power was removed
The Yellow blinking light will turn off:

When the thermostat detect C wire power
Forty minutes after a yellow light event

Turn off CT100 Filter reminder

Turn on CT100 filter reminder
To set a reminder, follow these steps:

  1. Press the menu button

  2. Press the filter button

  3. The display will show how long it has been since your thermostat was installed or since you last reset the filter reminder

  4. Press and hold the Filter button for three seconds. The display will change to Limit

  5. Use the left and right arrows to set the number of days between filter alerts. Setting the reminder to 0 will turn off the reminder.

  6. Press the house button twice to return to the main screen

Dude, you rock! Thanks!

So did that work for you? And if so, was the reminder set to 0?

Hey, what happened to the pics? Nope, didn’t work. No ‘filter’ button after pressing ‘menu’.


Yeah, the “swing” is there, but not the “filter”. Must be disabled through firmware or something. .