Expert's Rating
Pros
- Wi-Fi adapter is built in, no additional-cost bridge required
- Compatible with Amazon Alexa, Google Assistant, and Apple HomeKit
- Easy-to-use mobile app
- Stylish industrial design
Cons
- Minimalist design limits the amount of information the device itself can display
- Not compatible with Samsung SmartThings (compatibility was added after our review)
- Wiring can seem confusing compared to the thermostat you’re replacing
Our Verdict
A stylish and high-tech choice for making dumb high-voltage heaters a whole lot smarter.
Mysa is one of the few manufacturers building smart thermostats for high-voltage heaters, including baseboard, fan-forced convector, and radiant ceiling types (Sinopé is the other big player). But the Mysa Smart Thermostat is a whole lot prettier than Sinopé’s offering, and it doesn’t require a bridge to connect to your Wi-Fi network.
It’s also more expensive, however, and since the types of heaters this and Sinopé’s thermostats are designed to control are not centralized, you’ll need to buy one for every room (or at least one for every room with a heater you wish to control). On the other hand, you’ll need to purchase Sinopé’s GT125 Wi-Fi bridge ($89.95 at Amazon) to add its thermostat to your home network (one bridge can service multiple Sinopé thermostats, as well as Sinopé’s smart lighting controls).
Updated June 14, 2019 to report that Sinopé has informed us that they have added support for Samsung SmartThings, but we have not reinstalled the thermostat to evaluate this feature.
If you have more than one heater that’s controlled by the same thermostat now, you can wire the Mysa in its place, provided the total load doesn’t exceed 3,800 watts. The Sinopé model we reviewed can handle loads of up to 4,000 watts.

Mysa’s mobile device app carries over the hardware’s minimalist design aesthetic.
The most striking aspect of Mysa’s product (especially in comparison to the Sinopé) is its clean white design, with a minimalist dot-matrix display and capacitive touch-sensitive buttons. It’s an aesthetically pleasing device that gives off a high-tech vibe without being overly distracting. On the other hand, it doesn’t report as much information as the Sinopé, which displays the day and date, the current outside temperature, and the programmed temperature in addition to the current inside temp.
The biggest technical difference between the Mysa and other smart thermostats is how you’ll wire it to your heater. Smart thermostats like this have internal components—such as a display and a radio for communications (a Wi-Fi adapter in the case of the Mysa)—that require constant electrical power. Some smart thermostats can siphon enough power from the electricity going to the heater to run these components, but the Mysa is powered directly by the line wire, with a second wire from the thermostat connecting to the load wire (supplying the heater), a third wire connecting to the neutral wire (going back to your electrical panel), and a fourth used for ground.
This sounds like a bigger deal than it is, but the installation can be confusing if you’re not paying attention. If you want to verify that your heater will work with this thermostat, you can run through this interactive compatibility script on Mysa’s website.
Setting up the Mysa app

Geofencing support means you don’t need to remember to change the thermostat’s settings when you leave home, and your heater should automatically warm the room to the desired temperature when you return.
The rest of the installation, using the Mysa app, is straightforward: The setup wizard helps you connect the thermostat to your Wi-Fi network, and then you move on to programming a heating routine. If you don’t want to set up an in-depth custom schedule, the app can apply a “quick schedule” based on statistical energy savings or answers to a series of questions about your schedule and temperature preferences.
Adding temperature-change events to your schedule is a simple matter of hitting the “+” symbol on the upper right of the Schedule page and picking the days, times, and temperatures.
Deleting a temperature change point, on the other hand, is a more manual process. If you’ve made a universal change to your schedule (say, to increase the temperature to 67 degrees at 7:00 p.m. every night), and decide later to delete that event, you’ll need to manually tap and delete that event for every night; you can’t just issue a blanket change.
If you’re setting up more than one Mysa smart thermostat, you can create “zones” that will have multiple heaters act in unison. If you’d prefer to skip the app altogether, you can make immediate one-time temperature adjustments by tapping on the face of the thermostat and using the up and down arrows.
Unlike the thermostat’s native display, the Mysa app tracks humidity, and it will offer options for an “eco” mode that automatically adjusts the temperature to save money. An ‘early on’ option, meanwhile, will preheat the room to assure that space reaches the desired temperature at the set time. Lastly, the app can perform in-depth energy-consumption tracking, which is a welcome feature.

The Mysa app makes it easy to program your desired temperature targets.
The Mysa can connect to Amazon Alexa Alexa and Google Assistant, and it’s compatible with Apple HomeKit and IFTTT. SmartThings compatibility is on the company’s roadmap has been added (but we have not evaluated it), and the thermostat supports geofencing. That can turn your heater on and off when you enter and leave a defined radius around your home, although this feature is currently hidden in the app’s Experimental Features menu.
When you add in the cost of the Sinopé GT125 Wi-Fi bridge ($90 at Amazon) that’s needed to make a Sinopé TH1120RF thermostat ($80 at Amazon) truly smart, Sinopé’s solution is more expensive than Mysa’s ($90 + $80 = $170). But you need only one Sinopé bridge for many Sinopé thermostats. Amortize the cost of the Sinopé bridge across, say, four thermostats ($90 + 320 = $410), Sinopé comes out on top—at least in terms of pricing, because four Mysa thermostats would cost $556).
All that said, the Mysa’s attractive industrial design, its sophisticated app, and its more robust smart home integration opportunities render it the better value in smart thermostats designed for high-voltage heaters (unless SmartThings compatibility is a must-have feature, or you’re also deploying Sinopé’s ZigBee smart lighting controls).