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Honeywell Comfort Control API


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Honeywell recently announced releasing a public API for controlling their thermostats called Comfort Control API as discussed here:


http://www.cepro.com/article/honeywell_ ... ermostats/


Has anyone seen any more details so that those of us interested in picking one up can get access to these thermostats? I tried signing up at Honeywell's site for more info, but since I am not a programmer representing any products, I have not received any info from Honeywell.






Honeywell Announces Cloud-Based Open API for Wi-Fi Thermostats


Tapping the Internet of Things, Honeywell’s Comfort Control API for WiFi thermostats will hasten integration with pro & DIY home automation systems such as Control4, Lutron, Smartthings, ifttt, others.


Honeywell’s Open API is being tested by Lutron, Control4 and others, opening the door for third-party home automation providers to integrate with Honeywell’s Wi-Fi thermostats via the cloud.


Soon, we should see Honeywell’s smart thermostats integrate with numerous home automation systems by tapping the Internet of Things. The company has announced a cloud-based open API, called Comfort Connect, for its Wi-Fi thermostats.

While the API so far has been implemented only by professional-oriented providers— Control4 (home automation), Lutron (lighting controls, motorized shades), Akuacom (Honeywell’s own smart grid solution) and Opower (smart grid platform) – Honeywell expects DIY solutions to follow.


Honeywell’s Brad Paine, director of product development, Environmental Combustion and Controls, tells CE Pro, “We have demand from both custom systems as well as DIY. … Honeywell offers both professionally installed products as well as DIY products and the web API allows integration of either.â€


Currently, Honeywell offers three Wi-Fi thermostats (known by different names depending on channel): the WiFi Smart Thermostat ($250 MSRP), WiFi VisionPro ($149) and WiFi FocusPro ($119).


The open API opens doors to a growing number of existing and forthcoming IoT service providers including ifttt, SmartThings, iRule, Alarm.com, Blacksumac Piper, WigWag , Ube and countless others.


So far, only a handful of other IP-enabled thermostat makers have opened their APIs to third parties. Ecobee and NetworkThermostat are two of them.


Most glaringly, Nest has not opened its API although I speculated earlier that the company might announce such largesse at the CEDIA Expo later this month. I have since tempered my expectations but we can always hope.


RELATED: Prediction: Nest Will Announce Open API at CEDIA 2013


Honeywell Integration


A leading provider of communicating thermostats, Honeywell has for a long time integrated its products with its own home-control systems including the Total Connect cloud-based security and automation service.


Over the past couple of years, however, we have seen more of an effort to deploy Honeywell Thermostats beyond the Honeywell ecosystem. For example, the company has rejiggered its VisionPro thermostat to incorporate a radio that communicates natively with Lutron’s RadioRa 2 lighting and shade controls. That product, announced a few months ago, is called the Lutron TouchPro.


But the Comfort Control API is a new initiative. Communications with WiFi thermostats happen at the cloud level, allowing third-party providers to tap into a wealth of energy-management information crunched and processed by Honeywell – without the need to tunnel into a user’s home network.


For more information on Honeywell’s open API visit http://www.ecc.honeywell.com/api


Currently the notice says: “Please leave your name and email below, and we’ll send you an invitation to join Honeywell’s Comfort Control API Program in the near future. We are aggressively moving through the invitation requests and anticipate that it will be a short wait before you receive your invitation.â€


At CEDIA Expo 2013:

Honeywell, booth #1510

Control4, booth #608

Lutron, booth #1127

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We can't wait to see what enterprising developers have in mind for utilizing the Honeywell Comfort Control API in their Home Automation projects. Let us know what you've done and share with as on Twitter @honeywell_home


- Zoe @ Honeywell




Is the Honeywell API available yet for us to include in our home automation projects? Some of use are ready immediately to buy a Honeywell thermostat to start integrating into our Systems and would love to share, but we can't do anything until we have a published API. I posted my email on Honeywell's Cloud API online request form last month, but have not heard back anything. I had assumed that it wasn't being released to home programmers yet...



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Hi Stik;


Our Comfort Control API is currently in Beta I and we are collecting users for Beta II. Stay tuned as we get closer to the Beta II launch and announcement, as there will be some pretty cool campaigns around that launch. Just know that the Beta II group won't be announced until early next year, but when it is, it'll be with some pretty big fanfare.


- Zoe Quadflieg @ Honeywell

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Can you give a little more info on the API's capabilities?


I previously wrote an app to interface Enviracom with the ISY by reverse-engineering the protocol and using the serial adapter.


It actually worked pretty well but was a cumbersome setup and was recently replaced with an ecobee. The big plusof this setup was the interfacing did not have to go out to the cloud.


I've now written a similar program for my ecobee.


ecobee's API is probably the worst experience I've had in home automation. It is cloud based and realtime data is unavailable (runtime data only gets updated every 15 minutes).


I'm hoping the new Honeywell API is a little more straight forward than ecobee's and enables faster feedback to help control HA systems.


Also, will any future "IAQ" type systems be available to use this API?

I need a system with a remote interface module (my previous was a VisionPro IAQ, ecobee is the same) - too many wires and sensors for local hookup.


If the API and hardware agree with my setup I would definitely explore writing another Honeywell program.

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  • 2 weeks later...

Hi there,


Thanks so much for commenting in this thread and sharing your experience with us. Since we are still in the BetaPhase for this API, we are not at liberty to publicly speak on the specific questions that you posed but we can say that your thoughts and expectations are in line with our anticipated offering for this version of the API. Please feel free to visit our registration website and submit your info:



Here's a link to our press release announcing our API: http://honeywell.com/News/Pages/Honeywell-Announces-Cloud-API-Program-With-Home-Automation-Software-Developers.aspx


Thanks again,

Zoe @ Honeywell

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We can't wait to see what enterprising developers have in mind for utilizing the Honeywell Comfort Control API in their Home Automation projects. Let us know what you've done and share with as on Twitter @honeywell_home


- Zoe @ Honeywell




I recently purchased the new Prestige 2.0 IAQ thermostat and I have to say that so far I am really loving it. In the coming weeks I will be purchasing the Redlink gateway for the app support. After watching some basic furnace operation videos on Youtube I found that installation was a breeze and I'm already seeing savings on my heating bills due to the increased accuracy of the thermostat, independent fan control, advanced scheduling, and additional sensors.


I chose it over Nest because of the press release announcing the Comfort Control API. Please add my voice to the growing roar of people asking that this not be a completely cloud based API. I find it discomforting (pun intended) that a device installed at my home and the accompanying data will only be accessible via the cloud. I am also concerned about privacy of this data, that Honeywell will inevitably profit from the gleamed meta-data that is provided by default because of the nature of cloud based computing, and the inherit trust we must place in Honeywell by granting them external control of our equipment in a system that we ourselves have no control over. With this in mind I ask that Honeywell at the very least provide basic local control and data logging capabilities with the OPTION of placing the system on the cloud.


Ignoring all of this, Honeywell is a name I trust and I am confident my concerns and those of others will be addressed when the final API is released. I look forward to seeing what this API can do! Simply based the current capabilities and expansion possibilities of the Prestige I will likely add additional HVAC equipment such as a dehumidifier (I have a fish room), whole house HEPA, and UV sterilization.


A note to UDI, I would gladly purchase a module based on this API. :D

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  • 1 month later...


Are you able to comment about UDI development with this API.

I need to integrate HVAC into my ISY home management network


My HAEcoSystem....

I have a 994i integrated with an ELK M1, ISY-ELK module using MobiLincHD, MobiLinc Connect, MobiLincPro for Android as UI.

Ubiquity IP cameras for surveillance

I use ELK temp sensors to monitor different areas.

I have 2 heat pump systems, one with a WiFi VisionPro8000 and an older Honeywell 7 day programmable


My 2014 enhancement plan

Replace the old Honeywell thermostat with a new Honeywell WiFi and integrate both thermostats it into my ISY system

Replace my TED energy management with Brultech and the ISY>Brultech module

Deploy MobiLinc GeoFence awareness for location based HVAC and lighting and energy management



Neal Nilsen


Hi bobluckey,




With kind regards,


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Honeywell now has two new Wi-Fi non Redlink models: RTH9580, RTH9590. The ...90 has voice recognition; the other, not. Otherwise, they are identical. I have been testing the ...80 and find it to work very nicely locally and remotely (using the Honeywell remote setup). Don't know about API's. Works in the Cloud...

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  • 1 month later...


Any updates regarding the API. I just installed a Honeywell wifi thermostat this weekend. While I do not see a big need to integrate this one with the ISY right now, I would like to have the option. I have two other thermostats that I am thinking about switching out but am going to hold off until I see what develops with the API.



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  • 1 month later...

I would like to see this working along with control for truefresh ventilation. Unfortunately truefresh cant be controlled in the Honeywell Redlink app either, but only going to the thermostat under ventilation then doing a timed boost up to 180mins. Major fail as that means you have to buy a separate simple Honeywell remote just to turn it on and max setting is 60mins.

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  • 4 weeks later...

Add me to the list of Honeywell Prestige 2.0 owners with a Redlink Gateway that would like some level of ISY control. Right now, these are on a separate system using the Total Control app. Pretty nice units and lots of customization through additional indoor temp sensors, etc. I have three units and the Prestige has alerted me when two of them have started failing based on performance.

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  • 1 month later...

I would love to see this developed as well. I just had a Mitsu 4 zone minispilt heatpump intsalled. It uses the Honeywell Focus Pro thermostats with Redlink. I would love to be able control the thermostats through the ISY and mobilinc app.

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  • 1 month later...

Is there any more information on using the Honeywell Prestige / Redlink gateway units with ISY?


I've been trying several thermostats to replace my Honeywell Visionpro 8000 non-communicating models and thus have bought and tried or am trying:


AprilAire 8800 - talks to ELK M1 (which talks nicely with the ISY) - hardwired to ELK panel, requires a protocol "box" to talk to ELK. No "app" just for T-stat. Must program etc... from T-Stat.

     Easy to implement rules / automation

     Only the basic controls, however, are implemented by ELK / ISY

     Not an "exciting" thermostat, but fairly configurable (not as good as it could be) - clearly based on Honeywell or is OEM'd by them

     Build quality is solid, size is normal to slightly large


Venstar T5900

     Uses wifi, has a cloud "app" which is pretty good

     Cumbersome to implement rules / automation (uses a server program - Venlink - between ISY and Thermostat - which is GREAT to have, but programming is a bit more tedious - I'll take it though!)

     Somewhat more complete set of automation controls available -vs- 8800, thanks to Venlink

     Has color touchscreen etc..., but lacks a bit of polish (often slow response to touch, display has a bit of flicker / slight  interference on occasion)

     Looks odd with wifi key on the side, build quality I'd say is adequate.

     Pretty small overall (may not cover wall holes / paint) - though the screen is used well and doesn't seem too small


Have not considered Z-Wave / Insteon units because of RF issues I don't want to get involved with.


Looking now at the Honeywell Prestige 2.0 / Redlink units.  These seem really configurable, but clearly the big issue is no control via automation it seems?  If something like Venlink for Venstar could be put together (in the absence of a "plugin" for ISY) it would be ideal.


It appears from this thread that Honeywell has made the API for this T-Stat available?


I'd be interested in anything else regarding these units and / or the possibilities of getting these talking to the ISY if anyone knows.



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I've been trying several thermostats to replace my Honeywell Visionpro 8000 non-communicating models and thus have bought and tried or am trying:






Thank you for conducting your experiments and sharing your results. I have my first T5900 and planning for my second. Your reviews and stories have been helpful (along with io_guy's). The automated thermostat space is changing rapidly and 'compare and contrast' summaries make a difference.


For the T5900, have you used the skyport mobile apps, if so what is your \view of them?




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Thanks for your comments.  I have used the skyport app, and it is pretty good.  Since I haven't used any of the other cloud-based apps yet (Honeywell's, for example) I can't really tell you too much, other than the app's graphics and ease of control are better than the ELK M1 (android) app I have (M1 Touch Pro).  Though the M1 app is pretty simple and works well, the Venstar (and I presume most of the other T-stat mfg. apps) are much more capable (i.e. can alter program schedules, set some of the "programming" parameters of the T-stat, see other temperature or humidity readings from other sensors).


While I think the Venstar is a capable unit and seems to have most things right, the build quality is bugging me a little (have to press the screen 2 maybe even 3 times sometimes for it to register a keypress - sometimes its OK with one press...)


It hasn't lost wifi link that I know of.


It has great adjustability and features (humidity control and adjustability is esp. nice), so I guess I should call it done and buy the 4 more that I need, but the Honeywell Prestige IAQ with the Redlink system (remote from T-Stat to HVAC equipment I really have no need for, but their "WiFi" T-Stats that look just like the Prestige IAQ don't have humidity control (though they may show it on screen) that I can tell) look like the most adjustable, capable and expandable - but can't be talked to by the ISY or the ELK!!


Also I'm unsure if the Honeywell API mentioned in this thread is for the Redlink units or the WiFi models, or both (if you have the Redlink / ethernet bridge)??


Honeywell has always made solid T-Stats  (at least higher end stuff) in my estimation, and the 5 year warranty on their stuff -vs- the 1 year on the Venstar coupled with the (perceived) build quality is a little concerning since I'd be buying a lot of it.



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I've tried the Venstar, ecobee and Honeywell web portals, they're all very similar in look and functionality.



Your "double press" issue with the Venstar may be the screen timeout.

The Venstar dims the screen a little after a certain amount of idle time (adjustment), after which your first press just wakes the screen.

Honeywell does the same thing (the older H touchscreens turned the screen off).


It's also good to remember that these are resistive touchscreens (not capacitive like a phone), so their press quality sucks in general.  The Honeywell and ecobee I tried were no better.


One huge advantage of the Venstar is that you (Venlink) connects locally, which is why I switched to it.

The ecobee, Honeywell and Nest (once they get working APIs) are all cloud based.

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Thanks for the insight.  I'm aware of the double-press to wake the screen, and that's not a problem at all.  The AprilAire 8800 (Honeywell based) is also like this, however my Honeywell Visionpro 8000's don't need the extra touch. Just pressing temp up/down etc... gets some presses, misses others.  Like you said, you actually have to PRESS, not just touch, the screen.


One other thing I've figured out - the screen flicker / interference effect is due to the Display Dimmer, if you have it set for something besides Brightest.  If you set it at BRIGHTEST, flicker goes away.  I didn't try every setting, but 70%-90% flickers.  Haven't looked that closely yet when it is on "Idle" dim, which I have set at around 20%.  Maybe it is just my unit that does this?


All in all, with the ability to do a lot of the programming and "button pushing" remotely, it's not really a deal breaker.  It just seems like the CPU running the T-stat is maxed out - the spinning fan symbol hiccups once in a while and I feel like the missed presses are related to the slow CPU also.


So the Honeywell API (Is it "out" - can you get it or do you have it?) requires commands to be sent to their (Honeywell's) servers, and then their servers relay any changes on to the T-Stat?  Kind of like "Venlink" residing on their machine instead of mine I guess.


I'd sure rather skip the cloud part for direct control, but the Honeywell has a few features / adjustments the T5900 doesn't have (control of fan speed in dehumidify mode, for example), ability to use wired and wireless temp / humidity sensors, monitoring of delta T if you want it, and 3 semi-programmable relays that can control other things relating to your equipment depending on how it is set up.  Almost too many parameters.


I think the T5900 has 95% of what I need, so I'm leaning that way, but I may buy the Honeywell Prestige IAQ / Redlink and try it out as well just to be complete, esp. if there is any possibility (even if only cloud) of integration with ISY or ELK.

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