A few months ago, I wrote a product review for the ecobee Smart Thermostat (along with complete installation instructions and photos) which had I purchased to remotely monitor and control the thermostat in my Utah house while I was away. Overall, my review of the ecobee was positive and I really like the product, but I also pointed out a couple things about the ecobee that didn’t like. My main issue was the absence of an embedded interface to allow users to control their thermostats without relying on ecobee’s hosted application, which meant that ecobee customers couldn’t access their thermostats if when ecobee’s servers went down.

My second big issue was the somewhat limited functionality of ecobee’s iPhone app. Don’t get me wrong, I dig the ecobee iPhone app. It has some great features and I love the fact that the app’s interface looks almost identical to the thermostat’s main interface. But my initial review listed a few annoying limitations of the iPhone app, and yesterday I discovered another one. Read on to find out what it was.

Installing an ecobee with a Heat Pump

Yesterday, I installed my second ecobee unit at our log home at the Lazy J Ranch in Eastern Washington. This house is actually the place I wanted an ecobee the most. It gets really cold in the winter there, and really hot in the summer. Usually, we show up, set the thermostat to a comfortable setting, then leave immediately to go grocery shopping while the house heats or cools, which can take a while depending on the extremity of the outdoor temperature. But not any more, thanks to my ecobee!

One of the advantages of the ecobee over other smart thermostats is that it doesn’t need a dedicated CAT5 cable. If you’re replacing an existing thermostat that has at least four wires (and nearly all of them do) and you have WiFi in your house (and anyone geeky enough to want this thermostat already does), you can use the existing thermostat’s wiring – meaning you don’t need to run any additional wires inside your walls. In a normal home, that’s good news. But in a log home, that’s great news, because fishing wire through solid logs is practically impossible.

Because the cabin is in a remote location, there’s no natural gas available (although thanks to a WISP, I do have high-speed Internet). So the HVAC system is very different to the one I have in Utah. The Cabin’s HVAC system is comprised of an older single-stage electric furnace (Lennox CB19-65-3P-TXV) with a newer single-phase outdoor electric Heat Pump (Lennox HP29-060-5P). The thermostat I replaced was one of the older brown Honeywell digital models.

Essentially, the most straightforward way to install an ecobee into any existing HVAC system is to follow these three steps:

Disconnect the existing thermostat wires from the furnace’s wiring terminals,
Use new thermostat wire to connect the ecobee interface unit to the same terminals on the furnace as the old thermostat, then
Use the existing thermostat wire that runs from the furnace room to the thermostat location to connect the ecobee interface unit and the thermostat.

Checking the Existing Wiring

So my first step was to check out the wiring of the existing thermostat to learn what connections I’d be using on the ecobee interface unit. I always take photos before re-wiring anything, so I can restore things back to their original state if I mess anything up. The existing thermostat wiring looked like this:

The existing wires are (clockwise from top left): Red->R (24V power), Pink->C (common ground), Yellow->Y (cooling), Orange->O (heat pump reversing valve), White->W2 (AUX heat), Green->G (fan relay), Brown->L (system monitoring – more on that later).

Next, I documented the existing wiring at the furnace terminals:

Another shot of the wiring:

As confusing as this looks at first, after staring at this mess for a few minutes I realized that there are only three sets of wires that I should care about in the above photo:

The brown cable exiting to the right contains the existing thermostat wires that run from here to the thermostat location upstairs.
The smaller brown wire on top contains a blue, green, and red wire that connect to an external fan control relay (which has a manual override switch for the fan and which also connects to some mechanized valves in the ducting).
The brown cable near the bottom-right corner contains a red, yellow, orange, white, and brown wire and runs outside to the heat pump.

Wiring in the ecobee Interface Unit

Before doing any wiring, I shut off power to the heat pump and the furnace. After mounting the ecobee interface module to the cold air return, I ran two new 7 conductor wires through the hole on the right and exposed all the appropriate ends with a wire stripper. I then began disconnecting the wires that ran upstairs to the thermostat and connecting the remaining wires to the matching color wires on one of the new cables – some connected to the terminal block on the furnace, others connected out to the heat pump (I used those same orange wire nuts). The only wire left without a match was the brown that used to connect to the L terminal on the old thermostat, and everything I could find online said I could simply tape it off. When I was done, I used the second new cable to connect red and black to the R and C terminals on the furnace to provide 24V power the ecobee interface unit.

Wiring in the ecobee Thermostat

After the interface unit wiring was done, I connected four of the wires from the old thermostat cable (Red, Black, Green, and White) to the 12V, GND, D+, and D- terminals on the ecobee interface unit, then went upstairs to wire the other ends to the ecobee thermostat wiring harness. After securing all the connections, I went back downstairs and turned on the power. The ecobee interface unit powered up, and cycled its lights. But the bottom “COMS” error light remained red, and the thermostat upstairs remained dark, which bummed me out. However, a quick check of my wiring revealed that I had accidentally connected the black wire as GND on the interface unit, but used the brown wire at the wiring harness. Switching to the correct ground wire solved the problem, and my ecobee sprang to life!

Setting up the Thermostat

First, I connected the WiFi, which was very simple and straightforward. I gave it the same email address and password I had used to register my first ecobee. Next, I stepped through the installation wizard, which was just as simple as it had been at my Utah house. I merely replied with different answers this time to match the different setup: 1 stage heat pump, 1 stage electrical furnace as AUX heat, etc.

Checking Online Access

When I opened the ecobee.com remote access site in my laptop’s browser, my new thermostat was available in a drop-down menu, alongside my Utah thermostat. I named the new one “Cabin” and then clicked around to finalize the programming and other options. All went without a hitch and ecobee has done a great job allowing their web interface to organize and control multiple thermostats. I created a group called “Vacation Homes” and put the Utah house and the Cabin thermostats in that group (I’m installing three additional ecobees in my primary residence, which will have their own group).

Checking iPhone Access

My next step was to see how ecobee’s iPhone app managed multiple thermostats. I fired up the app, which said: “Authenticating…” then “Looking for thermostats…” then “Received thermostat list…” This was encouraging, since the the words “thermostats” and “list” leads me to believe that the app supported multiple thermostats on the same account. However, after a few seconds, the Vacation Mode screen popped up, which looks like this:

I suppose I understand why this screen appeared, since my Utah ecobee technically is in Vacation Mode. However, it seemed that the only way to access any other thermostat on my account via the iPhone app was to press “OK” on this screen, which would put the Utah house back in Standard Mode, which would heat the house while I’m not there. I tried “swiping” my finger from right to left to see if the screen would page over to a new screen and display the other thermostat (like flipping through photos on the iPhone). Sigh… it didn’t work. 🙁

I was hoping that perhaps it was merely user error on my part, so I called ecobee Tech Support. After a short wait, I was connected to a representative. After explaining that I had just installed a second ecobee thermostat, I asked if their iPhone app supported multiple thermostats. He said “yes.” Sweet! I asked how to display a second thermostat if one of them was in Vacation Mode.

An awkward silence…

He replied that unfortunately, the iPhone app didn’t allow management of multiple thermostats if one of them was in Vacation Mode. Double sigh. He went on to explain that this was a known issue, and that support for that feature was planned in the future, etc, etc. I thanked him and hung up the phone.

Turning Off Vacation Mode

Still interested in checking the app’s functionality, I decided to press the OK button on the Vacation Mode screen anyway, explore the multi-thermostat interface, and then re-enable Vacation Mode on the Utah thermostat. After pressing OK, the standard ecobee interface appeared, but with a new Thermostat icon on the bottom:

Pretty cool! Pressing the yellow Thermostat icon displayed the following screen:

“Gables” is the name of my Utah thermostat, and “Cabin” is the extremely creative name I gave the one at the cabin. 🙂

I was able to select either unit and display the standard interface, exactly as I would expect, although it sometimes took more than one press to keep the desired thermostat selected before pressing Done.

Turning Vacation Mode Back On

The humorous irony of the situation is that while Vacation Mode blocks the ability of the iPhone app to manage any thermostats on the account, the iPhone app does allow a user to re-enable Vacation Mode. Pressing the More icon in the main interface displays the following screen:

Pressing the Vacation icon displays a screen that allows the user to set the Vacation Mode options:

Pressing the Done icon on this screen returns the iPhone app’s interface to the Vacation Mode screen, where the only available option is to press OK.

Checking the web interface confirmed that the system had gone back into Vacation Mode, but also showed me that during the time I was testing, the furnace turned on Stage 1 heat for 3 minutes. Grrr! That probaby cost me a whole nickel! 🙂

Update: This iPhone App Bug is a Big Deal

I noticed last night (1/4/11) that an updated version (1.3) of ecobee’s iPhone app had been available in the iTunes App Store since 12/23/2010. I was surprised that ecobee hadn’t sent a notification email out to their customers about the app update (I know they have my email address because my ecobee emails me customized alerts), but that’s beside the point. Hoping the iPhone app Vacation Mode issue might be fixed, I enthusiastically updated – but the problem still remains in the updated version. On a positive note, however, the issue I reported about needing multiple presses on the the Select Thermostat screen seems to be fixed!

After updating the ecobee iPhone app last night, and thinking about its issues a bit further, I decided to add this new section to this blog post one day later because I realized something: this Vacation Mode bug is a bigger deal than I first thought, especially for those of us who own multiple ecobees. Basically, if a single thermostat in an account is in Vacation Mode, the iPhone app is essentially rendered useless. Now, before someone comments on this post to say this problem isn’t really that big a deal, and that the workaround is simply to take the ecobee out of Vacation Mode, make whatever changes I want, and then re-enable Vacation Mode (exactly as I did in the above example), let me ask you this: what happens if two or more of my ecobees are in Vacation Mode? That’s not a far-fetched scenario. My primary residence alone has three thermostats, so when I leave that house I’ll want to put all of those ecobees in Vacation Mode.

As a test, I used the web interface to put both the Cabin and Utah ecobees in Vacation Mode, then I opened the iPhone app. As expected, I got the Vacation Mode screen. However, I didn’t know if pressing OK would turn Vacation Mode off for both thermostats or just one of them, because nothing on the Vacation Mode screen displays any thermostat name.

It turns out that pressing OK must turn off Vacation Mode for whichever thermostat is set as the “default” – which happens to be my Utah thermostat. However, I couldn’t find anywhere in the web interface that allows me to choose which thermostat is the default, and therefore I can only assume that since the default isn’t chosen alphabetically (Cabin would comes before Gables), it must be whichever thermostat has the lower ID number in ecobee’s database (which would essentially be whichever one was first used to establish your ecobee.com account). My friend, business partner, and Chief Technology Officer, Steve Cook will back me up me when I say that type of “don’t worry about it – nobody will ever notice it” database sorting occurs all the time in Internet apps. But not in ours. Just ask SteveC how freakishly obsessive I am about database sorts being based on something that makes sense. It’s always extra work for him, but it keeps my OCD from flaring up. 🙂 But I digress…

Once the Utah thermostat was out of Vacation Mode, I was able to control it as normal, and the web interface confirmed that the Cabin thermostat remained in Vacation Mode. When I used the iPhone app to click the yellow Thermostats icon and select “Cabin,” the Vacation Mode screen re-appeared (again without any thermostat name, but by process of elimination I knew it was the Cabin one, since the Utah one was still in Standard Mode). I pressed OK to disable Vacation Mode for the Cabin thermostat, and was then free to manage either thermostat using the app, as long as they were both in Standard Mode.

However, while I was able to use the iPhone app to take all thermostats out of Vacation Mode (ignoring the fact that it was impossible to know which one I was turning off until after the fact), the app only allowed me to put one of them back into Vacation Mode. Once I went through the steps in the app to enable Vacation Mode for one thermostat, the Vacation mode screen appeared and the app was useless. I was then then forced to use the web interface to re-enable Vacation Mode for any other thermostat on the account, which has to be done using a standard web browser, particularly since ecobee.com’s web interface doesn’t display properly in the iPhone’s Safari browser, and the options that are displayed are difficult to change.

Final Thoughts on this Install

Just as I did with my original review when I installed an ecobee in a newer HVAC system with a 2-stage gas furnace and an external A/C unit, I found connecting the ecobee Smart Thermostat to an older HVAC system with a heat pump and electric furnace to be very straightforward and well within the ability of the average DIY tinkerer. After a second install, I’m still a big fan of ecobee’s products, and plan to install three more of their thermostats in my primary residence.

I’m still tinkering with some of the setup options at the Cabin (how long a compressor delay to use, whether the HVAC system or the Thermostat should control the fan relay, the minimum outside temperature to allow the heat pump to turn on, etc.), but for now things seem to be working fine. I’m going to investigate whether I can wire the L wire into one of the sensor terminals on the interface unit (I believe it either alerts the system when the heat pump is in defrost, or maybe when AUX heat is in use) and I want to look into whether I could possibly connect the two electrostatic air filter wires that currently run upstairs to a separate box with LEDs for “Wash” and “Check” (it’s currently mounted next to the thermostat, but I’d like to remove it altogether).

Once again, my verdict is that while the ecobee isn’t without its limitations and minor annoyances, I can still recommend it, with the hope that 2011 will bring some solutions to those few limitations – the big being, of course, direct remote management and a number of fixes to the iPhone app (which I’m happy to beta test for you, if anyone at ecobee is reading this).

Please feel free to leave questions or your own experiences with an ecobee Smart Thermostat in the comments. I’ll keep writing about mine, because they appear to be popular. According to my blog’s statistics, ecobee posts are the third most popular subject on my site, and are read by a few hundred people every day. Thanks, guys!

10/23/2011 Update:

Due to repeated requests about an Ecobee users discussion forum, I’ve started one myself. If you’re an Ecobee owner, enthusiast, or would just like to join the conversation, you can subscribe here: