Radio Thermostat (2GIG) CT100 Plus Thermostat

Forum rules

Questions about hardware that can be controlled by Indigo (but not through the interfaces and plugins listed). If Indigo doesn't support some bit of hardware you're interested in, and you don't find a 3rd Party Plugin for it, add it to this forum. Be sure to include links to as much information as you can find about it.

Note: adding it here does not mean we're going to add it - in fact it's possible one of our 3rd party developers may decide to write a plugin for it. We add hardware/features based on a lot of different factors beyond just having a request for it.

Posted on
Tue Feb 12, 2019 11:41 am
dduff617 offline
Posts: 455
Joined: Jul 05, 2006

Re: Radio Thermostat (2GIG) CT100 Plus Thermostat

Regarding Radio Thermostat products, I have come to agree with Jay. I can't recommend them. Unfortunately, I can't point to a solid alternative, either, at least not based on first-hand experience.

Summary of my (rather sad) experience over the last 10-12 years with thermostats:

Insteon I installed several variants of Venstar thermostat with Insteon module in two different houses. Thermostat generally worked ok, although comms were never very reliable. Bogus sensor data was sent and (apparently) bogus commands were occasionally received that caused the unit to jump to absurd setpoints at times. My last remaining Insteon unit's reliability went from bad to worse a year ago and I finally had to replace it.

Nest. Nice hardware, somewhat expensive. Uses Wi-Fi for comms. Connects you to the Google/Nest cloud (for better or worse) and (to some degree) ties you into their universe, including their concept of home/away. Initially these were well-supported via Indigo plugin called Nest Home, however now there are many limitations and incompatibilities using the device with Indigo. Basic setpoint setting and sensor tracking still work well. Functionality beyond that ("eco" settings, home/away assist, etc. ) are generally not supported properly.

Z-Wave CT100 Plus. Nice feature set, at least on paper. Reports humidity. Reasonable price. They are not trying to embed a "smart" hub inside the thermostat (in contrast to Nest) and did entail any dependence on outside cloud services (also in contrast to Nest). Unfortunately, the comms started out working well and (at least for one of my two devices) now seems to not be working reliably/correctly.

I don't relish the idea of having to purchase a new thermostat (yet again). For my next thermostat, I'll go with something that has solid recommendations from others in this forum and ideally is from a company with solid background in HVAC. Since Z-wave continues to evolve fairly rapidly, it is tempting to look at newer models (i.e., models that are at least Z-Wave Plus). In my opinion, the selection of Z-wave thermostats on the market is extremely limited - there are a handful of them available, many of them old (> 5yr) models, most made in China and sold by companies I've never dealt with before (RemoteTec, GoControl) and/or rebranded. Exceptions are Trane (I think made by RCS?) and Honeywell. Honeywell Lyric T6 (model TH6320WF2003/U) looks like an interesting candidate - anyone have experience with it?

I've established initial contact with Radio Thermostat about my problems with CT100-plus. I'll report back if I get a breakthrough there such as establishing I just had a bad unit or (hopefully) getting firmware updated to address the unreliable comms issues that I'm seeing.

Posted on
Tue Feb 12, 2019 12:01 pm
jay (support) offline
Site Admin
User avatar
Posts: 15303
Joined: Mar 19, 2008
Location: Austin, Texas

Re: Radio Thermostat (2GIG) CT100 Plus Thermostat

I have 2 Trane thermostats (both XR524) and they are rock solid.

I had a Honeywell WiFi thermostat and had no end of WiFi/network communication errors with it. It was very picky about WiFi, and would randomly drop from the network (requiring me to pull it from the wall and plug it back in). The total connect web service was down at least once a month. When the web service came back the thermostat sometimes would need power cycling. It was a mess. I'm done with devices that are cloud-based for which I need reliable operation: I replaced the Honeywell with a Trane several months ago and it's been solid (I have another upstairs that I've used for 2+ years without any issue).

Jay (Indigo Support)
Twitter | Facebook | LinkedIn

Posted on
Tue Feb 12, 2019 2:12 pm
Dual offline
Posts: 82
Joined: Feb 05, 2019

Re: Radio Thermostat (2GIG) CT100 Plus Thermostat

My 3 RTCoA CT-100 thermostats were all rock solid on the Iris platform. No issues. More than 3 years with each of them. I am swapping then over to Indigo. So far so good after a few days only.

Sent from my iPhone using Tapatalk

Posted on
Tue Apr 02, 2019 4:18 pm
dduff617 offline
Posts: 455
Joined: Jul 05, 2006

Re: Radio Thermostat (2GIG) CT100 Plus Thermostat

Thanks to Matt, Jay, and others who contributed on this thread.

My final status was that I had two Radio Thermostat brand CT100-plus units . One is working well. The other was working well EXCEPT it would not transmit state changes (Heat-on, heat-off) for some reason. Both devices had identical versions and firmware, etc. (at least as visible via Indigo).

I pretty much ruled out comms issues. I tried the reset-and-start-over approach. I contacted manufacturer and learned there is essentially no warranty of any kind on these. Manufacturer told me contact the seller; seller offered only 30-day refund/exchange. I ultimately had to give up on the one that wasn't working - I really wanted to be able to track duty-cycle of my HVAC system (using Grafana Home Dashboard plugin) as well as to have triggers that ran based on system state.

The original point of the thread (as guidance for someone looking to buy this unit) might be moot, as this thermostat doesn't really seem to be available any more. I personally would not really recommend it, based on unreliable performance and lack of backing from the company.

I just bought a new Honeywell unit, in case someone looking to buy a Z-wave thermostat might be interested, I'll start a similar thread on my observations for it.

Who is online

Users browsing this forum: No registered users and 0 guests