SmartThings Community

Sensi Thermostat

Any recommendations on ST supported thermostats that don’t need a C-wire?

Well, I just logged in to look at what you all are seeing. I don’t have a lot of time to dive deep into it today. BUT Sensi changed at least the log in portion considerably.

The actual URI has changed, and it appears that they’re moving away from free and easy access to “Multiple Thermostat Manager” That is $1 per month per thermostat? Any of you hear anything about that?

I can still log in to the web portal by scrolling down and clicking the already a user. But it likely means the reverse engineering needs to start over. :frowning:

I have a friend whose system does not have a “C” wire but uses a Nest Thermostat. The thermostat is only being charged when the system is heating or cooling. I do remember once during winter leading to spring we took it off the wall to charge due to lack of heating and cooling during that period, but that only happened once after about 2 years of having it. The Ecobee 4 has a power kit that can be installed if you don’t have a “C” wire.

I received an email about it.

I spent a bit of time inspecting the network requests in chrome / Firefox at the Sensi website, and it appears that the thermostat data is getting transmitted over websocket vs the browser polling a JSON endpoint. If we are able to reverse engineer the new oauth bearer token authentication step, it may be challenging to retrieve thermostat data given websockets aren’t supported in SmartApps. Though there may be alternative / legacy data retrieval apis still available to support the official Sensi mobile apps and wink / Google home / Alexa integrations.

Now I can only think of one quick hack (if you have a Google Home) to get through this before we can figure out new way to connect:

Bottom line is we need a google home and a laptop or Rpi… and then we can send custom commands using webCoRE to control it and do automation using pistons.

This additionally gains us a notification functionality to all the things happening in smartthings realm.

Add me to the list of unhappy Sensi customers. I have two and noticed they ar stopped working a day or two ago with my smartthings routines. I’m glad to have searched for this thread to get answers. Tonight I set up the scheduling which I haven’t used in a year or more. We are gone most off the day but the weekends. It was nice to have it change with our presence sensors. I do see the app has geo fencing but I don’t have the app installed on my wife’s. Can you do geo fence and scheduling? I’ll go play with that. I’m tempted to get a cheap zwave thermostat. I have 2 Sensi ones and haven’t heard about a charge.

Hold fire on that, Google disabled broadcasting via the API due to security issues until they can fix it

It looks like the multiple thermostat manager is aimed as a solution for managing multiple devices across multiple locations. I don’t think it’s intended to replace the out of the box free app.

Didn’t read through the thread, if I understand correctly broadcast under same network is still possible? Yet if broadcast is blocked does that mean commands are blocked too?

Unfortunately not. Broadcasting from the SDK is disabled regardless of location. They should hopefully be rolling a fix out by next Friday all going well

Hello folks,

I am so glad I found this discussion thread because I had been so frustrated last few days trying to figure out why all of the sudden my Sensi thermostat no longer runs on my ST routines.

So the fact that Sensi still works with Alexa skills then shouldn’t we be able to connect to the same API endpoint? I think the way that Alexa connects to Sensi is about the same as how Kirk’s smartapp does today is by connecting to Sensi’s API and authenticating with the Sensi user account.

I was able to temporarily Rube Goldberg my Sensi thermostat automation back together. But it’s a band-aid for now. You will need to setup, if not already, 1) Wink mobile app 2) Stringify (an IFTTT competitor) mobile app .

Sensi has a supported integration with Wink. Luckily, you are able to download and setup the Wink mobile app without having a Wink Hub. I linked my Sensi Thermostat within the Wink App, and setup a couple Wink “Shortcuts”, which are similar to SmartThings Routines, to mirror my Sensi Thermostat temperature settings. In my ST Routines, I have them trigger virtual momentary switches, for example; SmartThings Routing “I’m Back” -> Turn on Virtual Switch “I’m Back Fired”. Then I am using Stringify (a IFTTT competitor), to consume the “I’m Back Fired” event and trigger the Wink “I’m Back” Shortcut, which set’s my thermostat to temperature desired.

This is most definitely a hack, and gives me much less customization than I had before. I was using WebCore to automate my HVAC logic, recirculate air, fire SMS warnings upon various conditions, etc, and none of this is achievable thru this solution. However, for simple Routine based automation, this is a band-aid for now until I replace the sensi w/ my new Z-Wave CT101 thermostat. Unfortunately, Sensi doesn’t fit my requirements anymore without our ability to integrate into ST.

It looks like this can be achieved with SmartThings -> IFTTT -> Wink as well, instead of Stringify in the middle. Still requires the Virtual Momentary Switch to be turned on via ST Routine though.

Thanks for the info John, I’ve used all of them actually. And I actually moved from wink to ST because I simply don’t like the lack of functionality wink has (I didn’t have wink hub so all through wink app).

Back then I used Stringify for a little automation too but I found the app is to clumsy and not intuitive. IFTTT is good for the simplicity and abundant support for different services.

The fact that I really don’t like this way (it’s good suggestion of yours indeed) is this involves too many middle men already. I just want to keep connection fast and simple, adding too many in between is not ideal.

That being said, I am still curious how you can trigger IFTTT from virtual switch? I know how to trigger IFTTT using webCoRE which would save me one route of automation if it’s coming from it :joy:

My understanding is, all these connections (official integration that is) require you to login using their portal and authorization before using it. There’s a contract between these services and sensi simply opens up the API for them. Since SmartThings is not supported by sensi, we have no way to go through this process because sensi would not allow SmartThings to do so.

That said if we actually can figure out how to get to the authorization page, they may be a huge step forward.


Please read thru this thread to get a conceptual idea of a virtual switch

It seems like we should be able to sniff the traffic on the Sensi phone app which is still using the free service. We may find out they they simply changed the server name the app communicates with.

Hi Kirk,
Sensi changed the API for their thermostat, will you update the code for the SM SmartApp?
this is the answer i got from them:

Thank you for contacting Sensi Technical Support. We do apologize for the issue you are having. Here is the new link: We also want to inform you that the skills are not going to work with the updated endpoint due to the legacy API no longer existing.


Hi sir. I’ve been using the Sensi integration happily for a few months now, but about a week or two ago it stopped working. I tried a few things without luck, so I deleted my thermostat to try to re-add it. However the thermostat no longer shows up to be added.

I was curious if you were aware of anything breaking recently? If not, I’ll keep trying.

Thanks much!

Yes, unfortunately sensi completely redid their website API. And they do not make it public. I reverse engineered the old one. But this new one is beyond my abilities right now. Maybe you could email sensi asking for the API specs and access. Couldn’t hurt.


1 Like