Emerson Sensi 1F86U-42WF & UP500W Thermostat Review

If you’re looking more for functionality than a sleekly designed thermostat, the Emerson Sensi Wi-Fi thermostat is an excellent choice.

The Emerson Sensi thermostat does not have fancy features, but for some people, this basic set of smart features is precisely what they are looking for.

It’s easy to install and in most cases does not require a C-Wire. You can also manage multiple thermostats from a single app.

Sensi Smart Thermostat, 100 Years Of Expertise, Wi-Fi, Data Privacy, Programmable, Easy DIY Install, Works With Alexa, Energy Star Certified, Mobile App, ST55

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  • Easy to install and setup
  • Great mobile application
  • Can manage multiple thermostats from a single app
  • Does not require a C-Wire (in most cases)
  • Up to 5-year warranty (if installed by an HVAC professional)


  • Does not have automatic an automatic scheduling feature
  • Basic fan control
  • No energy consumption and savings reports

Emerson Sensi Thermostat Key Features

7-day Flexible Scheduling

One of the critical functions in today’s thermostats is the ability to schedule your home temperature based on the time and day. This feature helps to maintain your home comfort when you are at home and save energy while everyone is away.

Programmable scheduling usually works nicely if you know approximately when you and your family members will be at home and when they’re not.

The Emerson Sensi thermostat lets you set a 7-day schedule for heating and cooling flexibly. You can set weekday and weekend temperatures, or you can program a custom schedule for each day. In the video below, you can see how you can schedule the Sensi thermostat:

The Sensi thermostat will also let you set the desired indoor temperature for any time of the day, as you can set up as many temperature adjustments as you like. You can create multiple schedules and manually switch to them whenever needed.

For example, you can program a vacation mode setting to save energy but also keep the house warm enough to maintain the proper home environment. Just before you leave for your vacation, you manually set the thermostat to that vacation mode, and your home will be kept at the optimum temperature that you set.

UP500W or 1F86U-42WF?

  • There are two versions of the Emerson Sensi Wi-Fi thermostat: DIY (UP500W) and PRO (1F86U-42WF). It’s the same device, only differing in the packaging and instructions.
  • The PRO (1F86U-42WF) version is intended for professional installers and has a five-year warranty. The DIY (UP500W) is for retail customers, and has a 3-year warranty. You can choose whichever you prefer, as they are same device.
  • My review is for both Emerson Sensi Wi-Fi thermostat models: DIY (UP500W) and PRO (1F86U-42WF).

Geofencing Feature

If a programmed plan doesn’t fit your lifestyle, you can override it with the geofencing feature. Geofencing is a way to automatically control the thermostat comfort mode and energy saving mode based on your location, which is provided by your smartphone’s GPS location.

The geofencing feature will save energy while you are away from home and provide excellent home comfort when you return. Before you can use the geofencing function, you’ll need to register your Sensi account and download the Sensi app to your iOS or Android smartphone or tablet.

When you travel from your home by more than 3 miles, the Sensi app will signal to the thermostat that it should switch to energy saving mode. It will lower the temperature by 3oF when the thermostat is in heat mode and will increase it by 3oF while in cooling mode.

When you are within a 3-mile radius of your home, the Sensi app will tell the thermostat to get back to the comfort mode (the temperature point you set before leaving your home).

If you have an unpredictable and ever-changing schedule, then the geofencing feature will help you to manage your home temperature and energy savings the smart way. It will automatically save energy when you’re away from home and also ensure that the temperature is in comfort mode when you return.

On the other hand, if your schedule is fairly fixed day-to-day or week-to-week, then the scheduling feature will fit your needs sufficiently. If something should change, you can adjust the temperature in the Sensi app from wherever you might be, as long as you have an internet connection.

Early Start Feature

On other thermostats, most people add a bit of extra time in the schedule for the heating or cooling system to warm up or cool down the rooms, thereby ensuring that the temperature is right at the required moment.

For example, if you wanted to be sure that the house was warm when you got up in the morning, you would add some extra time for the heating system to warm up the house before you got out of bed. With the Emerson Sensi thermostat, however, you don’t need to do that.

The Early Start feature will predict how early to start the heating or cooling system, so the temperature is right at the time you’ve set. It is quite a smart feature that ensures you have the best comfort possible in your home.

Boost Function

This feature provides you with the maximum heating or cooling whenever you need it. This feature can be activated by a rapid 3oF manual adjustment from the set temperature.

When the Boost is turned on, all available heating or cooling stages will be utilized. When the Boost is turned off, the thermostat will use additional heating and cooling system stages based on the specific system performance calculations.

The Boost feature provides maximum efficiency for both heating and cooling. The Boost feature is available only if your HVAC system has more than one stage of heating or cooling. Generally, this kind of system would be a heat pump with an auxiliary heat source.

Email Alerts

One of the reasons why people purchase smart Wi-Fi thermostats is for the control of your home comfort. The Emerson Sensi thermostat provides more than just the ability to set heating and cooling schedules and to control the thermostat over the Sensi mobile app.

This thermostat also helps you ensure that you are informed when something unexpected happens, giving you even more control over your home. The Sensi thermostat sends email alerts about critical conditions regarding your home climate to the email address associated with the Sensi account.

Whether your family members are sensitive to significant temperature fluctuations, you are a property manager, or you have a vacation home, it’s crucial to detect critical conditions that occur in those properties.

To help with that, the Sensi thermostat will send you email alerts so you can immediately take steps to fix the problem. The Emerson Sensi thermostat will provide you with the following alerts.

Humidity Alert

The alert will be sent when humidity at your home is higher than 78%. These conditions can happen when, for example, a window or door is open.

Loss of Heating or Cooling Alert

This alert is an early warning about your heating and cooling system not working efficiently, and therefore isn’t able to achieve the set temperature.

The loss of heating alert indicates that your home temperature has dropped by 5°F during a heating cycle. The loss of cooling alert means that your home temperature increased 5°F during a cooling cycle.

High or Low Home Temperature Alert

This alert means that your home is not being heated or cooled when your heating or cooling system is on. The low home temperature alert is triggered when the temperature is below 45°F.

The high home temperature alert indicates that your home temperature is above 99°F. The email alerts on Sensi thermostats are enabled by default.

The high and low temperature and humidity alerts are not adjustable. Loss of heating and loss of cooling alerts are based on your thermostat settings.

If the condition which triggered the alert still exists after some time, the alert is sent again. Some of the warnings are triggered daily, while others can be sent weekly.

Sensi Mobile Application

The Sensi mobile application is available for Android and iOS mobile phones and tablet devices. With this application, you can quickly view and adjust the temperature for your thermostat and also set and switch the schedule.

Scheduling the thermostat is an easy, quick process, with lots of possibilities to customize your home comfort. The full scheduling guide can be found on the official website.

Sensi Smart Thermostat, 100 Years Of Expertise, Wi-Fi, Data Privacy, Programmable, Easy DIY Install, Works With Alexa, Energy Star Certified, Mobile App, ST55
  • PRIVACY PROTECTION*: Sensi won’t sell your personal information to third parties
  • EASY DIY INSTALLATION: Use the built-in level and step-by-step app instructions for a quick installation. Works with HVAC equipment found in most homes. Common wire (c-wire) is not required in most applications
  • SAVE ABOUT 23% ON HVAC ENERGY*: The ENERGY STAR-certified Sensi smart thermostat can help you save energy with features like flexible scheduling, remote access, and usage reports
  • SMART MAINTENANCE: Sensi can help monitor the performance and efficiency of your HVAC system by delivering valuable usage reports, alerts about your equipment, and maintenance reminders like filter replacement
  • SIMPLE CONFIGURATION: Looks and feels like a thermostat. Has buttons and fits the same space as a traditional thermostat so you don’t have to patch and paint your walls

You can also adjust the temperature manually or turn on the geofencing feature for smarter home climate control. With the geofencing feature, your device’s GPS location will be used to determine whether the thermostat needs to enable home mode for best comfort or away mode for energy savings.

Managing Several Thermostats

If you own several rental properties, multiple houses, or offices, the Emerson Sensi thermostat will make your life easier by allowing you to control several thermostats from a single mobile application.

With the single Sensi mobile application or a web portal, you can monitor and adjust several Sensi thermostats as long as you have an internet connection on your mobile phone or computer.

Integration with Smart Home Ecosystems

The Emerson Sensi Wi-Fi thermostat integrates with Amazon Alexa for voice control. Currently, it supports setting specific temperatures, as well as raising or lowering the temperature by a few degrees.

Integration with the Wink smart home platform allows you to control all the Wink-compatible devices, such as lights, door locks and garage doors, with the same Wink mobile application.

Adding the Sensi thermostat to the Wink application is a very easy and straightforward process. Just open the Wink app, click “Add a product,” then select Sensi thermostat and follow the instructions to finalize the set-up.

Emerson Sensi Thermostat Installation

Installation of the Emerson Sensi thermostat is guided through the Sensi mobile application. During the thermostat installation, you’ll need to create a Sensi account within the Sensi app and register your thermostat.

Failing to register the thermostat might result in it not being fully integrated with the Sensi mobile app. We suggest making sure that you have registered your device to enable its full functionality.

Before starting the installation, be sure that you have written down the access code found on the back of the Sensi thermostat. The access code is also enclosed as a separate leaflet in the thermostat box.

After you have completed setting up the thermostat, the Sensi application will show the current mode and temperature. Full instructions on the Sensi thermostat installation and setup can be found in the installation guide.

C-Wire or No C-Wire?

C-Wire is a low voltage power wire that most Wi-Fi thermostats use for their features to work. Many homes don’t have C-Wire because the older mechanical thermostats do not require it.

The Emerson Sensi thermostat is one of the few Wi-Fi thermostats that do not require a C-Wire (in most cases). Therefore, installation of the thermostat should be quick and easy.

However, if you have a C-Wire, then it is recommended that you connect it. Please note that heat pumps, cool-only, and heat-only systems will require connecting the C-Wire.

Compatibility with Heating and Cooling Systems

The Sensi Wi-Fi thermostat can work with the majority of combined heating and cooling systems even when there is no C-Wire available. The thermostat can work with the following heating and cooling systems:

  • Forced hot air systems powered by gas, oil or electric
  • Heat pumps
  • Hot water boilers
  • Radiant heat systems
  • Systems of up to four stages of heating and two stages of cooling

The Emerson Sensi thermostat will not work with:

  • Line voltage or electric baseboard heating
  • Millivolt heating
  • Communicating or proprietary systems

You can check your wiring and HVAC system compatibility on the Sensi website.

Downsides of the Emerson Sensi Wi-Fi Thermostat

No Learning nor Automatic Scheduling Features

The Emerson Sensi Wi-Fi thermostat will satisfy most of the people who are looking for home climate control and automation. It has the basic features, including 7-day climate schedule programming possibilities and geofencing functionality to adjust the temperature when you are home and when you are away.

However, if you are looking for a smart thermostat that you install and forget, this might not be the right one for you. It will not learn your climate preferences over time as, for example, the Nest learning thermostat does.

To manage your home climate with the Sensi smart thermostat, you will need to either set the schedule, enable the geofencing feature, or manually set the temperature through the Sensi mobile app.

Fan Control

The fan control with the Sensi thermostat is quite basic. It has two options: auto or on. Auto mode means that it will only turn on when heating or cooling is on. The on mode will keep it running all the time.

There are no other options in between. The problem with these options is that you probably don’t want to run the fan continuously. On the other hand, the auto mode might not keep your home properly ventilated, because the heating and cooling system might not be on often or long enough.

Energy Consumption and Savings Reports

One of the reasons why you buy a smart thermostat might be to save some money on the smart control of your climate and reduce energy consumption.

There are some Wi-Fi thermostats, such as the ecobee3, that provide quite extensive reporting on energy consumption, energy savings, and your HVAC system performance.

Unfortunately, the Emerson Sensi smart thermostat does not provide such information on your home’s energy consumption or how your heating and cooling system is performing. Hopefully, that feature will be introduced in the future.

Final Verdict

The Emerson Sensi is an excellent overall choice if you are looking for a basic smart Wi-Fi thermostat within a reasonable price range. It does have 7-day schedule programming, geofencing functionality, and remote control of your thermostat over the Sensi app.

The thermostat is easy to install and easy to use. We recommend choosing this smart thermostat if you are looking for something simple to upgrade your mechanical or programmable thermostat.

In most cases, it does not require a C-Wire, so if that is the case in your environment, you probably should consider the Emerson Sensi Wi-Fi thermostat for your home.

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