ecobee Reviews Thermostats

Review: ecobee Smart Si smart thermostat

Our ecobee Smart Si thermostat rating:


Smart Si at a Glance

It might be the lowest-cost thermostat in this list, but it offers loads of features, including usage reports, companion apps, and easy scheduling.


  • Easy to create a schedule through drag-and-drop web interface, much faster than the “learning” process on a Nest
  • Costs $100+ less than Nest, Lyric, and ecobee3 with few (if any) sacrifices
  • Detailed usage reports with Home IQ (free!)
  • Outdoor & indoor temps displayed on unit’s screen
  • Slim and unobtrusive design looks like a traditional thermostat, might suit your home better than a shiny “modern” thermostats
  • Optional system alerts and reminders (maintenance, outside temp. range, low/high humidity, etc)
  • Fine control over temperature min/max range, cycle times, heat differential (sometimes called “swing range”)
  • Works with or without a C-wire – use the power extender kit for systems without (included in the box)
  • Fan control


  • That ain’t a touch screen – but most people won’t care, because the app and web portal are pretty good
  • For systems without a C-wire, the [separately purchased] power extender kit is required
  • Can only set temp by 30 min intervals (not 10 or less, like some thermostats)

Our Rating

We think the Smart Si is great overall and award it 4 out of 5 stars. To earn a higher rating, we’d have wanted to see a no-C-wire workaround included in the box rather than sold separately, and maybe a larger screen since there’s quite a bit of faceplate area going to waste. That’s just getting nitpicky though – read on to see why the Smart Si is one of our favorites.

Everything you need, nothing you don’t

A lot of people discover the ecobee Smart Si after having trouble with the Nest. Either the Nest struggles to stay connected, or can’t handle their dual fuel system as adequately as they’d like, or can’t get Nest working with their C-wire. But the Smart Si isn’t an “also ran” consolation prize, it’s a full-featured smart thermostat with all the goodies you’d expect, and none of the cruft you pay $100+ more for on competitor products. With an average rating of 4.5 stars out of 5 on, we feel the Smart Si is a worthy competitor to the Lyric and Nest.

If you haven’t heard of ecobee, don’t feel bad – the Toronto-based company has mostly marketed to professional HVAC installers since its debut in 2009, not joe schmoes like us. (Though, even that’s changing since their Sept. 2014 introduction of the ecobee3 – read our ecobee3 review here.)

The Smart Si lacks a touch screen, but there’s still plenty of information on the screen, including weather and HVAC system settings. The screen and buttons are back lit, too.

A “Budget” Thermostat that Outshines Pricier Models

We call the Smart Si a “budget thermostat”, but there really aren’t many sacrifices here. If you really, really want a shiny yo-yo for your wall, by all means, go ahead and get a Nest or a Lyric. But that’s about all the extra $100 buys you!

The Smart Si is a remotely accessible and configurable thermostat that looks like, well, a thermostat. The Smart Si doesn’t feature a touch screen, but you can still do all the usual thermostat stuff via the buttons at right. The companion app and web portal are fully featured and it’s just easier to sit down at a computer or phone and make changes there.

Features include:

  • Daily program (awake, away, home, sleep)
  • Precision temperature control with customizable swing ranges
  • Temp display (Celsius/Fahrenheit)
  • Clock display (12 hr/24 hr)
  • Touch and alerts volume
  • Screen brightness
  • Standby brightness
  • Hold duration
  • Heating and cooling temp ranges
  • Smart recovery heat/cooling enabled/disabled
  • Fan minimum “on” time
  • Alerts for high/low temp, high/low humidity
  • Access control
  • Reminder intervals for HVAC maintenance, filter replacement, UV lamp
  • Which email address(es) to send alerts to

Plus, the ecobee Smart Si generates data reports (in the web portal) showing HVAC usage, comparisons between outdoor temp and indoor temp, humidity levels, and more. You can even download this data as CSV (comma separated values) – if you’re a big nerd like us! 🙂

Most WiFi-enabled thermostats run anywhere from $200-250 a piece, and some models (like the Honeywell Lyric) don’t even generate usage reports or give you as much control over your system’s settings and send you alerts when your home’s temp goes outside your desired range (Nest can’t do either of those).

One caveat: Like other smart thermostats, the Smart Si requires a C-wire. If your system lacks a C-wire (and it’s good to figure this out before surprising someone with a smart thermostat of any brand), you’ll need to buy a Power Extender Kit from ecobee ( link) or a Venstar Add-a-Wire adapter.

ecobee Smart Si unboxed – note the Power Extender Kit is NOT included with a Smart Si (it is, however, included with the ecobee3).

ecobee Tech Specs

Model Number

  • EB-SMARTsi-01


  • Main unit: 5.5″ wide x 3.2″ tall x 1.0″ thick

Wireless (Wi-Fi)

  • 802.11b/g/n @ 2.4GHz
  • WEP, WPA, WPA2

Nearly all wireless routers meet these standards.

Smart Si System Compatibility

  • Conventional (2H/2C)
  • Heat pump (3H/2C)
  • Gas, oil, electric
  • One-stage aux heat
  • Dual fuel systems
  • C-wire systems (out of the box) and systems without a C-wire (must add Power Extender Kit, or Venstar Add a Wire, or run new wires)

More Smart Si Info & Reviews

The Bottom Line

The ecobee Smart Si is a fantastic device that gives you exactly what you want out of a smart thermostat: complete control over your HVAC system and remote access to all its settings. Even though it costs a good $100 less than its major competitors Lyric and Nest, the Smart Si manages to pack in more features.

ecobee Smart Si and companion app shown on iPhone

The Smart Si is a smart choice for your home!

Check current ecobee Smart Si stock and prices on

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ecobee Smart Si smart thermostat
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6 replies on “Review: ecobee Smart Si smart thermostat”

We have one and wish it won’t break because if it does good luck trying to get help!
We have been having problems with ours and months later nothing has change even more I had to fight for my right to a free service as it stipulates on my contract! NEVER AGAIN,

I have been getting replies with try this and try that on the fluctuation of the temperature. I have tried everything but the last one stating that it is sensitive to the temperature being by the return air and to close the return air vent off.

Really?!? No solution and it’s been 4 days of going back and forth. This is not cost efficient. It rarely cools to what it is set to and then bounces up and down on what the internal temp shows.

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