Clear answers.


From simply adjusting the temperature to scheduling an upcoming vacation, you can find all the answers to your GLAS® questions here. Or you can call our customer service line, 1-833-297-GLAS (4527).


What is a C-wire?

A C-wire is a wire in your HVAC system that provides power to your thermostat.

If you do not have a C-wire, don’t worry. Use the included adapter and the installation instructions to convert your 4-wire system to a 5-wire system to power your GLAS thermostat.

Note: Double-check your current wiring for a C-wire as wires can sometimes be hidden in the wall.

Do I need the included adapter?

If you do not have a C-wire, you will need the adapter to power your GLAS thermostat.

Note: Double-check your current wiring for a C-wire as wires can sometimes be hidden in the wall.

What comes in the box?

In your GLAS box, you should find:

1. GLAS Thermostat

2. Optional backplate

3. Optional 4 to 5 wire adapter

4. (2) 1.5-inch Screws

5. (2) 1-inch Screws

6. (4) Drywall anchors

Where can I find GLAS’ warranty information?

To view GLAS’ warranty information, click here.

What does the Air Seal do and why do I need it?

Often, the section of the wall that a thermostat is installed on is shared with the airflow path of your heating and cooling system, or a device can be installed on a drafty exterior wall. In both of these cases, air flows through the wall that is a different temperature than the air in your room.

The air seal helps provide a tight seal to reduce the amount of air flowing across the GLAS device and impacting its sensors. In addition to reducing undesired airflow, the air seal provides a small amount of additional insulation, helping reduce the impact of the wall temperature changing as the flowing air changes the wall temperature.

We strongly recommend installing the air seal on your device, even if you do not suspect it to be necessary.

It doesn’t look like my wires will fit through the Air Seal, can I increase the size of the wire hole?

No, the Air Seal is not designed for modifications and increasing the size of the opening will reduce its effectiveness. The air seal is made from a pliable material that is designed to stretch and accommodate a bundle of up to ten 18-gauge copper thermostat wires, while still blocking airflow. After installing the Air Seal on the back of your GLAS device, it should be possible to push the wire bundle through without modification.

Can I mount my GLAS device in any orientation?

No, GLAS must be installed horizontally with the display at the top of the device.

The current temperature of my home does not appear correct, why is that?

Numerous factors impact the temperature that is sensed by your thermostat. Depending on installation location, how the device is mounted, the type of wall material, and many other factors, GLAS may sense a temperature slightly different than the actual temperature in your space.

If you did not install the Air Seal on the back of your GLAS when installing your device, we strongly recommend doing so to prevent airflow in or out of your wall that could impact the sensed temperature. GLAS also requires the front cover to be installed on the device to accurately sense temperature in your home.

After double checking the installation, sometimes external factors will continue to impact the device, and an adjustment is needed. You can apply an offset to the sensed temperature by navigating to Settings -> Comfort -> Temp Display and adjusting the Temperature offset to match the displayed temperature on your GLAS to another external thermostat that you rely on to calibrate the temperature.

We strongly recommend waiting for a few hours after installation before adjusting the offset to ensure that the sensors have fully adjusted to the environment. When adjusting the offset, we recommend not using handheld infrared temperature sensors as a reference, as they often have multiple degrees of error tolerance in their readings.

What does the Restart option do?

Selecting Restart will trigger the device to shut down and reboot, without changing any settings. Typically, you should not have to manually restart your device, but if you suspect something is wrong, a restart is a great first troubleshooting step.


What does the Factory reset option do?

Selecting Factory reset will trigger a full reset of the device back to factory settings. This process will erase all settings on the device, and you will be prompted to run through initial configuration after the process is done.

The factory reset process may take up to 20 minutes to complete, during which time your device will go through multiple stages and you may see blank screens from time to time. Please be patient and allow the process to complete. Your device will be ready to configure again once you see a screen with the GLAS logo and a Tap to continue button.

I need to know the device’s Wi-Fi MAC address, where can I find it?

The Wi-Fi MAC address is printed on the label on the back of your device. Alternatively, you can get the MAC address from a running device by navigating to Settings -> Support -> Device info.

Creating a User Account

Why should I create a user account?

Creating a GLAS user account gives you the ability to access your thermostat from anywhere. Using the web or mobile app, you can adjust your setpoints, edit schedules, view air quality, and change your temperatures.

Do I need a user account?

A user account is not required for GLAS, but without it you will be unable to access great features like remote access, simple control of multiple devices, and extended energy savings reports.

If I already have a Microsoft Account, can I use it?

To remotely access your GLAS device, control multiple locations, and take advantage of advanced reporting features, you will need to create a GLAS account. Your Microsoft Account will be necessary in order to take advantage of Cortana on your device to control GLAS and other smart home devices that work with Cortana. Don’t have a Microsoft Account? Don’t worry, you can easily create one on device while you set up Cortana.

Air Quality

Where do I find air quality?

To access air quality information, swipe left from the home screen and select air quality.

In air quality, you will find reporting on tVOCs, eCO2, and Humidity. When connected to Wi-Fi, you will also be provided with reporting on outdoor allergens, the Air Quality Index (AQI), and UV Index.

What does air quality measure?

Air quality monitors your indoor and outdoor air quality. Total Volatile Organic Compounds (tVOC), Equivalent Carbon Dioxide (eCO2), and Humidity are measured inside your home. When you are connected to Wi-Fi, the outdoor allergens, Air Quality Index (AQI), and UV Index in your area are also measured.

How can I find out more information about my current air quality?

To access air quality, swipe left from the home screen and select air quality, you will be directed to indoor air quality. By tapping on VOC, CO2, or RH, you can get more detail of each. By swiping to the left you will see the outdoor air quality where you can also tap to get more detail for allergens and smog.

What are tVOCs and why are they important?

Total Volatile Organic Compounds (tVOC) include a wide range of natural organic chemical compounds, such as carbon monoxide, methane, and benzene. Unhealthy levels of these chemicals can have respiratory, allergic, or immune effects both indoors and outdoors.2

Why is air quality important?

Air quality is important for maintaining personal and home health. Pollutants and allergens can cause respiratory and immune irritation. Unhealthy levels of these chemicals can have both short-term and long-term effects. Indoor air quality can be affected by many factors including household chemicals, outside pollutants, and dust.3,4

By being aware of your current air quality and taking steps to improve it, you can prevent adverse health effects and keep your home safe and healthy.

What is humidity and why is it important?

Humidity is the amount of water vapor in your air. Proper levels of humidity are important for maintaining personal and home health. Extremely high or low levels of humidity can cause damage to your building fixtures, such as hardwood floors, and discomfort for occupants.When connected to Wi-Fi, GLAS will recommend the optimal humidity for the current outdoor temperature, and work to keep your home at those target levels if you have an auxiliary device that can impact humidity such as a humidifier, dehumidifier, or ventilator.

What are allergens and why are they important?

High levels of outdoor allergens, such as pollen and mold, can cause sneezing, itchiness, and runny nose or eyes.

What is Air Quality Index (AQI) and why is it important?

Air Quality Index (AQI) is a measurement designed to inform you of the current air pollution outside of your building. When the AQI is high, respiratory and immune complications may occur.4

Why is GLAS reporting my air quality as fair or poor?

Many things can cause reduced air quality in your home. The most common source of CO2 and VOC are from people and animals breathing, cooking, and use of chemicals, such as household cleaners or paints. GLAS’s internal air quality sensor monitors your home’s long-term indoor air quality, allowing you to keep tabs on your home’s overall air quality and take action to improve it when necessary.

Can GLAS improve air quality in my home?

GLAS can improve your home’s air quality if you have ventilation equipment installed in your home. The auxiliary (AUX) terminal of your GLAS can be used to operate ventilators, including energy-recovery and heat-recovery ventilators. These devices use fans to exchange stale air with fresh air from outside, and in the case of the energy- or heat-recovery varieties, can do so in a very energy-efficient manner. GLAS uses its air quality sensors and information about outdoor temperature and humidity to intelligently operate your ventilator to maximize air quality and minimize energy usage.

I have a ventilator in my home, but it’s not connected to my thermostat. Can GLAS still help control my air quality?

Many ventilators engage the furnace fan, instead of having a separate fan for the ventilator. With these installations, any time the furnace fan operates, your ventilator will also operate to bring fresh air into your home.

Without a wiring change, GLAS can still use this system to manage air quality by enabling Minimum hourly fan runtime as well as Smart Circulation features. This will allow GLAS to manage your home’s air quality even when heating or cooling is not running, but also avoid needlessly running your fan and ventilator.

However, we recommend having a professional modify the installation so that GLAS can directly operate your ventilator. This way, GLAS can save you significant energy by only ventilating when the air quality needs to be improved.

Can I install a ventilator in my home so GLAS can improve my air quality?

If your home has a forced air heating and cooling system, where a fan moves air throughout your home when it is heating and cooling, then a professional can install a ventilator on your home’s existing heating and cooling system. The installation would involve installing ductwork for the ventilator in your return air duct, and two vents to the outside of your home.

Your local York authorized heating and cooling professional can make a personalized recommendation for your specific home, but typically we recommend a York Affinity Energy Recovery Ventilator for homes located in the southeast US, and a York Affinity Heat Recovery Ventilator for homes located elsewhere in the US, or in Canada.

What is “Smart Ventilation”?

Smart Ventilation is a feature available when GLAS is configured to control a ventilator and is turned on by default. When enabled, GLAS will intelligently control your ventilator to only operate it when air quality is poor, ventilation can help assist with cooling or heating, or to dehumidify in the winter. We recommend using Smart Ventilation with your ventilator to maximize your indoor air quality while minimizing energy usage.

Can GLAS help improve air quality if I do not have a ventilator?

If your home does not have ventilation equipment, GLAS cannot directly improve the air quality in your home. Besides contacting your local York authorized heating and cooling professional about installing a ventilator, we recommend making use of the Minimum hourly fan runtime feature as well as Smart Circulation. When both of these features are enabled, GLAS will work to distribute air throughout your home when poor air quality is detected by the GLAS device. While this won’t reduce the level of pollutants in your home, it will help reduce areas in the home with exceptionally reduced air quality, such as your living room when you’re entertaining large numbers of guests.

Is there anything I can personally do to improve my home’s air quality?

Yes, there are many actions that you can take to improve your home’s air quality. Below are some very effective ones that we recommend:

– Whenever it’s nice outside, we recommend turning off your GLAS and opening your windows to let fresh air into your home. Not only will your air quality improve, you’ll save energy by not running your cooling or heating system.

– When cleaning a bathroom, turn on the exhaust fan to help remove some of the contaminants from the cleaning products. And, if your kitchen has a cooking vent, turn it on whenever cooking or cleaning your kitchen. For extra benefit, crack a nearby window while operating a kitchen or bathroom exhaust fan.

– Whenever possible, reduce the use of aerosol sprays, perfumes, and candles in your home.

Does the air quality sensor in GLAS sense airborne particles, such as pollen or other allergens?

The air quality sensor in GLAS can sense volatile organic compound (VOC) gases but does not respond to airborne particles. When connected to Wi-Fi with a valid postal code entered, GLAS provides information about outdoor allergen levels to help you understand your potential impact. While GLAS cannot react to indoor allergens, we recommend that allergy-sensitive customers install a high-MERV filter during allergy seasons to improve their home’s air quality.

What is Equivalent CO₂, or eCO₂?

The air quality sensor inside GLAS measures volatile organic compounds (VOCs), and one of the VOCs measured by the sensor inside GLAS is hydrogen (H2). GLAS uses the sensed H2 levels in the building to estimate the level of CO2.

What type of air filter should I use in my home?

The higher the MERV rating on a filter, the fewer contaminants – including dust and pollen – will get through the filter. However, higher MERV filters cost more to purchase and more to operate by reducing airflow and causing your furnace or air handler’s fan to have to work harder. For most homeowners, a basic fiberglass filter is sufficient. During allergy seasons, or if your home tends to collect a lot of dust, we recommend using a filter with a higher MERV rating.

Can GLAS tell me when to replace my air filter?

Yes, GLAS can notify you when it’s time to change your air filter. Two options are supported – “Auto” or “Manual.” We recommend “Auto,” which calculates when the filter should be replaced based on runtime of your heating and cooling system. If you want to be reminded simply on a time interval, regardless of the operation of your heating and cooling system, then you can select “Manual” and select the number of months to be reminded in. When the filter needs to be changed, GLAS will generate a notification that will pop up occasionally until deleted, giving you periodic reminders if you’re unable to change the filter immediately.


Can I manually turn my fan on with GLAS?

Yes, GLAS supports “Auto” and “On” modes for your fan.

– When in “Auto” mode, GLAS will automatically run your fan as necessary with heating, cooling, or as otherwise necessary. When in “On” mode, GLAS will continuously run your fan.

– After selecting “On,” you can optionally select a specific amount of time to run the fan for before going back to “Auto” mode.

Can GLAS continuously run my fan when I’m home or sleeping?

Yes, GLAS supports a feature called Continuous fan when home, which when enabled will cause GLAS to operate the fan continuously when your device is in a “Home” or “Sleep” state. To configure this, navigate to Settings -> Comfort -> Air Quality

Can GLAS help ensure air is periodically circulated through my home?

Yes, GLAS supports a feature called Minimum hourly fan runtime. You can set this to a certain number of minutes that the fan must run for each hour when your thermostat is not in an “Off” mode. If your system does not operate the fan for at least the specified minimum duration due to heating or cooling, GLAS will turn on the fan to circulate air throughout your home.

What is “Smart Circulation”?

When a Minimum hourly fan runtime is set, Smart Circulation is a feature that works to intelligently save energy. When GLAS senses that your home’s air quality is good, it will not enforce the minimum hourly fan runtime. This saves energy by not needlessly circulating air throughout your home when the air quality is already good. When Minimum hourly fan runtime is configured, Smart Circulation is turned on by default.

Schedule and Occupancy

How do I create a schedule?

From the home screen, swipe left to access quick view and select schedule.

Your device will assist you in setting up your wake and sleep times, and creating events.

How do I create an event?

1. Select the “plus sign” in the upper right corner of the calendar view.

2. An away event allows you to place an event with your preselected away set points for a specified start and end time.

3. After adding the event, it will appear on your schedule.

I received an error when trying to schedule two events at the same time.

Scheduled events cannot overlap because the thermostat is only able to respond to one event at a time. If you would like to change the temperature in your space at a scheduled time, you can edit your existing event or delete the event and replace it with a new one.

How do I edit temperature preferences?

To edit your temperature preferences, go to Settings>Comfort Preferences>Temperature Settings and select the temperature setting you would like to adjust. You can edit your preferences for Home, Away, and Sleep.

Can GLAS automatically sense my presence?

Yes, GLAS has a built-in occupancy sensor that is used to determine if someone is home. When enabled, which it is by default, GLAS will use the sensor to intelligently switch your device between Home and Away states to ensure comfort when you are home and energy savings when you are away.

Over time, GLAS will begin to learn your home’s typical patterns and intelligently use the sensor to switch between Home and Away states. GLAS uses the sensor in conjunction with your schedule to ensure that your home won’t switch to an Away state while you’re asleep, or that you won’t wake up to a cold home if you sleep in a bit.

I’m leaving my home for a few days, can GLAS help me save energy while I’m away?

Yes, GLAS supports scheduled vacations. Simply navigate to Settings -> Vacation on your GLAS device or the mobile app and schedule the time that you will be away from your home. GLAS will automatically transition to an Away state for the duration of the vacation, and then return to your schedule when your vacation ends.

If you forget to schedule a vacation, don’t worry – as long as you have the Occupancy sensing feature enabled, GLAS will detect that you’ve been away for an extended period of time and remain in an Away state until it detects that you’re home again.


What is “Arrival Anticipation”?

When you set up a schedule in GLAS, you tell the device when you wake up, leave, return, and go to sleep. But not everyone’s schedules are the exact same every day, and some days you may not return home until hours after your scheduled return time.

Typically, GLAS will wait to transition from a scheduled Away state to a Home state until the occupancy sensor detects that you’ve actually returned home. While this can save energy, it might also mean returning to a warmer or cooler home than you’d like.

By enabling Arrival Anticipation, GLAS will transition to the Home state at the end of a scheduled Away state, even if you haven’t returned home yet, ensuring that your home is comfortable when you return.


What is “Pre-Start”?

Pre-Start learns how your heating and cooling system behaves over time and uses that to intelligently start your heating or cooling early so that your home is back to your Home temperature preferences when a scheduled Home period begins. When enabled, Pre-Start will always activate at the end of a Sleep period.

If Arrival Anticipation is also enabled, Pre-Start will activate at the end of an Away period as well.

Auxiliary Devices

What Auxiliary devices can GLAS control?

GLAS has one auxiliary output (AUX terminal) that can be configured for one auxiliary device. The following equipment types are supported:

– Ventilators (including Energy Recovery and Heat Recovery)

– Humidifiers (including bypass, fan-powered, and steam)

– Dehumidifiers

GLAS also supports configuring the auxiliary output in “On while occupied” mode, which will turn the auxiliary output on anytime the device is in “Home” or “Sleep” modes, and off when it’s in the Away state.

What can GLAS do with a ventilator?

GLAS uses its advanced sensors to make great use out of ventilation equipment. When controlling a ventilator, GLAS will:

– Help improve air quality in your home

– Assist heating and cooling (based on outdoor conditions) to reduce energy costs

– Dehumidify in the winter to reduce frost and condensation on interior windows

What can GLAS do with a humidifier?

GLAS can control all types of humidifiers to increase humidity in your home during the dry winter season. Bypass and fan-powered humidifiers that work in conjunction with your heating system are supported, as well as steam humidifiers that can run even when heating is not running. You can manually set the humidity setpoint, or, when connected to Wi-Fi with a valid postal code entered, GLAS can automatically operate your humidifier to the optimal humidity for the current outdoor temperature.

What can GLAS do with a dehumidifier?

GLAS can control dedicated dehumidifier appliances. Dehumidifiers that are built into your heating and cooling system and work alongside the fan are supported, as well as standalone devices that can operate on demand. You can easily specify the desired humidity in your home, and GLAS will work to keep it at that level. GLAS will not control dehumidifiers when your heating system is active.

What is the “On while occupied” Auxiliary device setting?

On while occupied is a mode aimed at advanced users controlling lighting or other specialty applications in a commercial setting. When GLAS is in a Home or Sleep state, the output will turn on. When in an Away state, due either to the schedule or the occupancy sensor, the output will turn off.

What is the type of signal output by GLAS to the AUX terminal?

GLAS outputs 24 volts AC when the AUX terminal is engaged. Power to the AUX device is sourced from the RC terminal.

What does “Auto” mode do for my Humidity setpoint mode?

During the winter, as outside temperatures drop, the optimal humidity level in your home changes.

– The colder it gets outside, the lower the optimal humidity level in your home is. While your home might feel more comfortable at a higher humidity, when the outside temperature is very cold, a low humidity is important for the health of your home.

– A low humidity level when the outside temperatures are very low is important to prevent frost on windows, and excess condensation in your walls leading to mold growth.

When Humidity setpoint mode is set to Auto, and your GLAS is connected to Wi-Fi with a valid postal code entered, GLAS will automatically adjust your humidity setpoint as the outdoor temperature changes.

Heat Pumps

Does GLAS support heat pumps with auxiliary heat?

Yes, GLAS supports controlling up to two heat pump compressor stages, as well as up to two auxiliary heat stages. GLAS can also control heat pump systems without auxiliary heat.

Does GLAS support dual fuel heat pump systems?

Yes, GLAS supports heat pump systems with electric, gas or oil auxiliary heating. GLAS’s internal algorithms optimize the operation of your heat pump and auxiliary heat so it always uses the most efficient type of equipment at all times, when your device is connected to Wi-Fi with a valid postal code entered.

What do the “Heat pump staging mode” options do for my heat pump?

Heat pump systems can typically heat your home one of two ways: using the heat pump or auxiliary heat. Depending on the outdoor temperature, the auxiliary heat might be an inefficient way to heat your home.

GLAS uses advanced algorithms to intelligently operate your heat pump and auxiliary heating to ensure your home remains comfortable while also preventing unnecessary energy usage. This adjustment gives you control over how your equipment runs, allowing you to adjust for the best blend of comfort and energy savings for your home.

What does the “Auto” option for “Heat pump staging mode” do for my heat pump?

When in “Auto” mode, GLAS will use the most efficient heating method to heat your home, but if it senses that your home is taking abnormally long to heat up, it may also engage the less efficient equipment to ensure your home reaches and stays at the desired temperature. This option is the default, and best for most users. GLAS will never needlessly use energy when set to this mode, but will ensure that your home is never uncomfortably cold.

What does the “Auto Savings” option for “Heat pump staging mode” do for my heat pump?

When in “Auto Savings” mode, GLAS will operate similarly to the “Auto” mode, but strongly prefer using the most efficient heating method to heat your home. Only if it senses that your home is heating at an exceptionally low rate, and more than a few degrees away from the desired temperature, will the less efficient equipment also be engaged. When this option is selected, GLAS will ensure that the least energy is used, but your home may take longer to warm up.

What does the “Manual” option for “Heat pump staging mode” do for my heat pump?

When connected to Wi-Fi with a valid postal code entered, GLAS allows you to specify the outdoor temperatures above which auxiliary heat will never run, and below which auxiliary heat will be preferred as a more efficient method of heating. After setting your Heat pump staging mode to “Manual,” you’ll be able to adjust the exact thresholds to match your equipment.

What types of heat pumps are supported by GLAS?

GLAS supports nearly all types of heat pump systems. During installation, if your system is identified as a heat pump, you will be prompted to select the type of heat pump that you have from the following:

– Outdoor Unit (air-sourced). These heat pumps are very prevalent in the southern US and coastal regions. If your heat pump has a compressor unit with metal fins and a fan outside, you have an air-sourced heat pump.

– Geothermal (ground-sourced). These heat pumps are common in high-efficiency homes and work by exchanging heat with the ground or a pond of water. If your house has a compressor unit in the equipment room, with pipes running out of the home, you have a ground-sourced heat pump

– Water-sourced. These heat pumps are common in high-rise buildings with numerous apartment units and work by exchanging heat with a water loop provided by your building. Typically, this type of installation would only be done by a professional installing the thermostat in your building.

What is a reversing valve, and how do I know what type I have?

The compressor system on your heat pump can either heat or cool your home by switching the direction that the refrigerant flows in your system. The reversing valve controls whether the system operates in a heating or cooling mode.

Depending on the model of your heat pump, some switch into cooling mode when the reversing valve is powered, and others switch into heating mode when the reversing valve is powered. It is important to select this correctly, or your thermostat will heat when it means to cool, and cool when it means to heat.

Often, the wire color is used to indicate the type – blue for B-Type and orange for O-Type. However, this is not guaranteed to be the case. We strongly recommend using the equipment test feature during the initial setup, to verify that you have the correct reversing valve type selected. During the test, if you feel hot air when it should be cooling, or cool air when it should be heating, press “No” when asked if you feel the right air coming from the vents, and then select “Yes” when prompted to reverse the reversing valve polarity. At that point, confirm that you now feel the correct air temperature coming from the vents.

Temperature Preferences

What are the temperature setpoints?

The Heat or Cool setpoint is the temperature the room has to reach before the heating or cooling will turn off.

What are home, away, and sleep temperature preferences and how do you set them?

To set your temperature preferences for home, away, and sleep, go to Settings>Comfort Settings>Temperature Preferences.

There you can select your desired heating and cooling temperature for each of the three modes.

Sleep mode is the temperature settings you select for your waking and sleeping hours. Your regular hours can be added to your GLAS thermostat so it will automatically adjust to your schedule and repeat daily.

Home and away are the temperature setpoints you select to maintain comfort while you’re home and save energy while you’re away.

How do temperature preferences benefit my space?

Temperature preferences conserve your energy by allowing you to adjust the space based on need and comfort level. As the environment changes, your system will respond to what you need. By adjusting these setpoints, GLAS will ensure you’re comfortable at all times. In the summer, the higher you set your away and sleep setpoints, the more energy your GLAS can save you. And in the winter, the lower you set your away and sleep setpoints, the more energy your GLAS can save you.

What are emergency heating and cooling setpoints?

Emergency heating and cooling are setpoints designed to protect your building from freezing or overheating. These setpoints will power on the system to protect your home, regardless of schedule or operating mode.

What is off mode?

To put your system into off mode, swipe left from the home screen and select off.

When you place your system in off mode it will not run, regardless of schedule or occupancy.

In off mode, you can manually activate the fan. However, hourly runtime tracking and air quality control will not activate.

Heat protection and freeze protection will still activate in off mode in the event that the emergency heating or cooling setpoint is reached.

What are the Temperature Preferences on the GLAS device?

Temperature preferences are the temperatures that the GLAS device will work to keep your home at for the different occupancy states of your home. As your home switches between Home, Away and Sleep states, GLAS will keep your home at these selected temperatures to keep you comfortable when Home and save energy when Away.

Can I select what unit of temperature to use on my GLAS device?

Yes, GLAS can display temperature in Fahrenheit or Celsius. You can easily change it by navigating to Settings -> Comfort -> Temp display and adjusting the Temperature unit on your device.

What is the temperature shown on the home screen of my device, and what happens if I change it?

The temperatures shown on the home screen of your device and the GLAS mobile app are the temperatures that GLAS is currently controlling your home to. Typically, these are set to the Temperature Preference for the current state of Home, Away or Sleep.

At any time, you can manually change the temperature in your home from the home screen of your device, the GLAS mobile device, or through Cortana. GLAS will then automatically switch back to the preset temperature preferences when your home next switches between Home, Away and Sleep.

Why can’t I have my cooling and heating set to the same temperature?

GLAS operates by cycling your heating and cooling system on and off to keep your home near the temperature preferences. GLAS requires a minimum of 2 degrees Fahrenheit, or 1 degree Celsius, between your heating and cooling temperatures, to prevent the thermostat from needlessly switching between heating and cooling modes. If you set a cooling or heating temperature too close to the opposite one, GLAS will automatically adjust the other temperature to be 2 degrees Fahrenheit away from the temperature you just adjusted.

To save money on your energy bill, we recommend that you pick a wider range for your temperature preferences so that your GLAS does not have to operate your heating and cooling equipment as often.

Energy Savings

How do I get energy savings reporting?

Tracking your energy savings is a great way to view your current usage and find ways to improve energy conservation.

To view your energy savings, swipe right from the home screen and select the energy savings button.

What information can I find in energy savings?

GLAS calculates energy savings by using an integrated learning model of your HVAC system. By connecting to Wi-Fi and entering your zip code, GLAS can identify a thermal model of your HVAC system after a few days of run time. Utilizing this information along with weather data coming from the cloud, GLAS will begin to calculate how much energy you would have used with a non-programmable thermostat.

You’re able to view your energy savings history up to 7 days and the reporting will update in real time to reflect the current day.

How can I improve my energy savings?

There are a few things you can do to improve your energy savings.

By creating schedules, activating occupancy detection, and selecting set points for home, away and sleep modes, you can ensure that the thermostat runs only when you need it.

To set your temperature preferences for home, away, and sleep, go to Settings>Comfort Settings>Temperature Preferences.

To set schedules and events, swipe left from the home screen and select Schedule. Follow the prompts to set up your schedule.

To ensure occupancy detection is activated, go to Settings>Comfort Settings>Scheduling Preferences.

Why should I take advantage of energy savings?

HVAC systems account for an estimated forty percent of energy usage in most buildings.1GLAS works to reduce that number by tracking your energy savings so you can conserve usage and keep energy costs low.

My GLAS device only shows me hours of runtime, not energy savings. Why not?

GLAS has a built-in, advanced algorithm to learn how your home’s heating and cooling system operates. These algorithms monitor how your system responds and predicts how much more your system would have had to run had it remained at the “Home” temperature all day.

To provide accurate data, this algorithm has many conditions that must be met before it can begin calculating energy savings. Your device must be connected to Wi-Fi with a valid postal code entered, and you must have a schedule setup on your device. Once those conditions are met, GLAS will require some time to learn a temperature model of your heating and cooling system, as it heats or cools your home.

Depending on how much your heating or cooling runs each day, it might take a few days to learn an accurate model and begin estimating your savings. Once GLAS is able to start estimating your energy savings, the icon will change from runtime to savings, and tapping on it will display a graphic of your energy savings in addition to runtime.

My energy bill did not go down by the amount GLAS shows. Why not?

Heating and cooling consumes a large amount of energy in your home, but it is still only a fraction of your home’s total energy usage. GLAS calculates an estimate of how much less energy just your heating and cooling system consumed than it would have, had it remained at your “Home” temperature all day. This calculation is based on learning the unique characteristics of your own heating and cooling system, but this calculation is not a guarantee of savings. Your actual energy savings can vary based on numerous factors, including weather, number of occupants in the home, and other devices/appliances operating in your home.

Voice Interaction with Cortana

How do I set up Cortana on my GLAS?

When you first purchase your GLAS smart thermostat, you will need to first set up your GLAS. As part of the GLAS setup, you will connect your GLAS to Wi-Fi. Connecting your GLAS to Wi-Fi allows your GLAS to download Cortana. You will receive a notification on your GLAS when the download is complete and you need to restart your GLAS to begin setting up Cortana.

From the Settings menu, navigate to General -> Cortana. From here you will need to use your Microsoft account information to log in and complete the on-screen instructions to complete your Cortana setup on your GLAS.

Why do I need to set up an account with Microsoft to use Cortana on my GLAS?

To use Cortana on your GLAS, you will need a Microsoft account because Cortana is a personal digital assistant that works best when it can learn about you and your activities by using data from your GLAS device and other Cortana-enabled devices, and other Microsoft services. You can choose whether to enable Cortana on your GLAS, and you can turn off Cortana at any time. You will use your Microsoft account to change Cortana settings.

Can I control GLAS through other Cortana-enabled devices?

Yes. After you set up your GLAS and enable Cortana on your GLAS, you can use any Microsoft Cortana-enabled device to control your GLAS smart thermostat. Please note that to use Cortana to control your GLAS, your GLAS and the other Cortana-enabled device both must be connected to the internet.

What kind of commands are supported through Cortana?

GLAS accepts commands through Cortana that begin with the wake word, “Hey Cortana,” and one of the following commands:

– Set volume to 50%

– Set <my GLAS device name> to 67 degrees

– Set <my GLAS device name> to heat

– Set <my GLAS device name> to cool

– Set <my GLAS device name> to auto

– Set <my GLAS device name> to off

– Set <my GLAS device name> thermostat to Home

– Set <my GLAS device name> thermostat to Away

– Make <my GLAS device name> warmer

– Make <my GLAS device name> cooler

– What’s <my GLAS device name> temperature

Additionally, you can use any other Cortana command from your GLAS, such as “Hey Cortana, what’s the news?” Subscribe to GLAS updates to learn about new Cortana commands for your GLAS.

Mobile Access through GLAS App

How do I get the mobile app for GLAS?

To get the mobile app for GLAS on your Apple or Android smart phone or tablet, navigate to the Apple App Store or Google Play Store and search for GLAS. You can also click the links below.

How do I connect my mobile smart phone or tablet to my GLAS?

To connect your mobile smart phone or tablet to your GLAS, you will need to link your GLAS mobile app and the GLAS smart thermostat. After you have downloaded the GLAS mobile app to your smart phone or tablet, log in with your GLAS account or tap Sign up to create an account. Once you have signed in to your account, use the Account Management screen to add a location and then the GLAS app will help you add a device, or tap on an existing location and then tap Add device. The mobile app will walk you through how to connect your app to your device with a pairing key generated on your GLAS smart thermostat.

Can I connect multiple GLAS smart thermostats to my mobile app?

Yes. You can connect 100 GLAS smart thermostats to your mobile app.

Can I control GLAS smart thermostats that are installed in different homes or locations from a single app?

Yes. You can control many GLAS smart thermostats in one home or many GLAS smart thermostats across many homes. Ensure that you use a clear naming system to help you know which location and which GLAS you are controlling at any time.

Which GLAS features are supported by the mobile app?

Your GLAS mobile app shares all of the same features as your GLAS smart thermostat. You can use your GLAS mobile app to control the temperature, heating or cooling mode, fan runtime, and other features.

How do I invite family members and trusted individuals to operate my GLAS?

From the Account Management screen on your GLAS mobile app, select Invite users. Then, you can enter the email address of an individual whom you want to give access to operate your GLAS.

Please note that anyone you give access to will have control over your GLAS; however, you will retain ownership of the device and the location and other invited users will not be able to remove your control.

Data Privacy and Protection

What kind of data does Johnson Controls collect through my GLAS?

Johnson Controls collects your equipment runtime and weather data to help your GLAS smart thermostat make smart decisions about how to heat and cool your home. This data includes how long your heating and cooling equipment runs to get your home to the desired comfortable temperature, air quality sensor data to help your GLAS determine when to run your fan or ventilator and keep your air fresh, and your weather data that is connected to your postal code to help GLAS figure out when it is beneficial to run a ventilator or cooling equipment to keep your home at your comfortable humidity and temperature preferences.

To get more information on what kind of data your GLAS collects, please consult the Privacy Notice on our website:

How is my data used by GLAS or Johnson Controls?

Johnson Controls uses your GLAS data to determine how to save you energy and extend the lifecycle of your heating and cooling equipment. This data helps your GLAS smart thermostat operate more intelligently with the information it gathers about your heating and cooling equipment.

To get more information on how your GLAS data is used, please consult the Privacy Notice on our website:

Who can access my data that is collected through my GLAS?

In a normal situation, only you and your GLAS smart thermostat have access to your data. In a situation where you need Customer Support, your customer service representative will have access to your current GLAS data based on the serial number of the device to help you quickly and efficiently troubleshoot your issue and get your GLAS back up and running.

To get more information on who can access your GLAS data, please consult the Privacy Notice on our website:

Professional Help

Can I get professional help to install my GLAS?

Yes. Through a partnership with installers in your area, GLAS can offer professional help to get your GLAS installed quickly and correctly from the very beginning. Use the Find an installer link on the website to enter your postal code and pick an installer.

Johnson Controls ensures that each professional installation comes from a trusted professional in your area, supports local businesses and gets the job done right.




Connecting to Wi-Fi

Will GLAS connect to my router?

GLAS requires a 2.4 GHz router for connection and operation compatible with 802.11 b/g/n networks.

Mobile hotspots and guest networks are not recommended.

Enterprise networks and captive portals are not supported at this time.

How do I connect to Wi-Fi?

Connection to Wi-Fi is part of the set-up process you will walk through during installation.

If you would like to make any updates to your Wi-Fi connection, go to Settings>General>Wi-Fi. Use the list provided to select the new network you wish to connect to and enter the password.

If the network you would like to use is not shown in the list, scroll to the bottom of the screen and select “Other”. Type in the name and password of the network you wish to connect to. The new network will be added to the network list.


How do I disconnect from Wi-Fi?

To disconnect from a Wi-Fi network go to Settings>General>Wi-Fi and select the “i” icon beside the connected network’s name. Select “Forget Network” and your system will disconnect.

If you have entered passwords for other networks, your system will automatically connect to them. If you would like to completely disconnect from Wi-Fi, repeat the process for all connected routers.

Why should I connect to Wi-Fi?

Connection to Wi-Fi allows you to get the most out of your GLAS thermostat.

Wi-Fi connection tracks the outdoor weather in your area to help you choose the most efficient temperature settings. Outdoor weather tracking also allows the thermostat to calculate your energy savings to improve your energy usage.

Using Wi-Fi also allows you to access your thermostat remotely from the web or your mobile device. With remote access, you can control your building’s temperature, adjust schedules, view energy savings, and power your system on or off.



1. United States Energy Information Administration, “Electricity Explained – Use of Electricity”

2. United States Environmental Protection Agency, “Volatile Organic Compounds’ Impact on Indoor Air Quality”

3. United States Environmental Protection Agency, “Introduction to Air Quality”

4. United States Environmental Protection Agency, “Air Quality Index (AQI) Basics”