Causes of Thermostat Blank Screen | Oak Lawn HVAC Services

Thermostat 101: Why Does It Show a Blank Screen Sometimes?


Most of us spend only half to a third of the day at home; the remainder is spent either at work or traveling there. Usually, we have a thermostat in our homes that turns the heating on or off based on the time of day or the interior temperature. 

But imagine getting home to find your place, either sweltering hot or cold. What happened?! You walk up to your thermostat controller only to discover its screen is blank. Are you serious?! Does this imply that your air conditioner, heat pump, or furnace is damaged? No, not always. In truth, the majority of the time, it’s a simple problem that can be resolved. How to fix a thermostat.

Why Have Thermostats at All?

This may appear silly to many, but it is a big decision for some. Some areas in the world where thermostats are not precisely needed or perhaps even suitable. But if the pros beat the cons, then the homeowner or landlord may eventually decide to get a thermostat installed. Now, why do you need thermostats at all?

Thermostats allow you to control your home’s central heating system through control panels integrated into the walls of your home. Nowadays, there are even ‘smart thermostats’ which can be controlled through a smartphone, tablet, computer, or voice activation through smart assistants like Google Alexa and Apple Siri.

This provides extreme convenience compared to manually turning the AC on and off to control the temperature in a room. What’s more, homes with thermostats and thus built-in heating systems have evenly distributed heating throughout the room or house.

Common Kinds of Thermostat

Modern thermostats come in four basic categories: non-programmable, programmable, Wi-Fi, and smart. The cost of the thermostats is increased as you move down the list that is below. With each thermostat, energy efficiency does, however, improve. Skip down to the smart thermostat section if you’re seeking a thermostat that offers the highest indoor comfort and optimum energy savings.

Common Kinds of Thermostat

Modern thermostats come in four basic categories: non-programmable, programmable, Wi-Fi, and smart. The cost of the thermostats is increased as you move down the list that is below. With each thermostat, energy efficiency does, however, improve. Skip down to the smart thermostat section if you’re seeking a thermostat that offers the highest indoor comfort and optimum energy savings.

Non-Programmable Thermostat

For folks who are rarely away from home, a non-programmable thermostat is ideal. The temperature can be manually changed to suit your preferences.

A simple thermostat is not programmed. You must alter the thermostat setting if you wish to change the temperature in your home. The temperature of your home cannot be set in advance to vary while you are away or asleep. However, a high-quality non-programmable thermostat can maintain your preferred temperature while achieving excellent energy efficiency by interacting with the heating system.

Programmable Thermostat

You may program a programmable thermostat to change the temperature throughout the day or at night. There are frequent daily and weekly settings on programmable thermostats. If, for instance, you only leave the house on Mondays and Thursdays, you can pre program the thermostat to maintain a more comfortable temperature during those days. The furnace won’t have to work as hard to heat the house. This lessens the unit’s wear and tear. It thus lowers energy consumption and maintenance expenses.

A programmable thermostat is excellent for people living in climates with extreme temperature variations. You know that winter nights may grow chilly, and days can feel warm because you live in Florida. You may set a programmable thermostat to make sure you’re warm in the mornings and cool during the day. You don’t have to manually regulate the thermostat every morning and evening to accomplish all of this.

Wi-Fi Thermostat

Wi-Fi thermostats connect to a wireless network. Your PC, tablet, or smartphone can all access the network. This enables you to change the thermostat’s setting from a distance. A programmable thermostat is also a Wi-Fi thermostat. Because you can override a preprogrammed temperature setting if you leave work early, it offers the utmost convenience. People who desire complete control over a home’s temperature setting even when away from the house, should use this type of thermostat.

Smart Thermostat

It is simple to combine a smart thermostat with various home automation devices and gadgets. The thermostat adapts the temperature as it learns your living habits over time. It will know your daily return time. It records the information as it spots patterns to maximize heating and cooling effectiveness. Many smart thermostats have voice control capabilities and are Alexa or Google Assistant compatible.

Smart thermostats are excellent for houses that value advanced technology and superior interior comfort. Like a Wi-Fi thermostat, a smart thermostat may be accessed from any internet-enabled device that works with the thermostat’s mobile app. Digital thermostats are much pricier than that of other styles of thermostats. But within a year or two, the money you save on heating and cooling costs will quickly pay for your investment. Even when it’s time to arrange maintenance on your HVAC system, a smart thermostat can notify you.

Dealing With a Blank Screen

The possibility of a thermostat going blank is one of their most prevalent issues. This issue can be even more annoying if you don’t understand why your AC thermostat is blank.

Old Thermostat

Thermostats can last anywhere from 10 to 20 years, but they wear out over time. Sometimes you have to get a new one. Sadly, if your thermostat is old, this could be the problem. If it is, make sure to have a professional install the new one since newer ones can be complicated, and you want to ensure you won’t have problems with it in the future.

Activated Safety Switch

There are safety switches built into HVAC systems in case something goes wrong. If one of your units’ safety switches is tripped, the transformer that powers your unit (and possibly your thermostat) will cut power. If it’s a furnace, you’ll need to call a pro to figure out what’s wrong and fix it. If it’s the heat pump or AC check to see if the condensate pan is full. This results in the safety switch being activated. Empty the pan and check to see if your unit and thermostat have power again. If not, you need to hire a pro.

Issues With the Wiring

Your thermostat may not work because of the wires that are connected to it. If they weren’t attached well at first or if the thermostat is in a room with a lot of foot traffic, people walking by can sometimes make the wires move. Our techs have also seen rodents chew on wires in attics, which can cause problems with the wiring. Since the wiring is directly related to electricity, you should call us to figure out what’s wrong and fix it. 

Dead Batteries

If your thermostat wall doesn’t have a “c-wire” or “common wire,” your thermostat is probably not powered by your HVAC system and uses batteries instead. If your screen is blank, it could mean the batteries need to be changed. If that’s the case, you’ll usually need AA alkaline or 3-volt lithium batteries to power the thermostat. Check to see what kind of batteries are already in it and replace them. Most thermostats have a symbol that says “low battery” when the power is low.

Open Furnace Door

Our techs run into this problem every once in a while. Some thermostats are more sensitive to this than others, but it is something you should check. If the door to your furnace isn’t shut, your thermostat will turn off. If this is the case, you should be able to get power back by closing the door securely.

Blown Fuse / Tripped Circuit Breaker

Depending on what you have in your home, a tripped circuit breaker or a blown fuse can be fixed quickly to get power back to your thermostat. A surge can sometimes cause this. If you check your electrical box and find that a circuit breaker has been tripped, flip it back. If there are fuses, you should change the fuse. Check your thermostat once this is done. If the power comes back on, you’re good to go. However, if the breaker trips again or the new fuse blows, you have a bigger problem with your HVAC system. You need to bring in a professional.

At Oak Lawn HVAC, we get a lot of calls from people having problems with their thermostats. When your thermostat screen goes blank, try what we have shared above and see if you can get it to work again. But if these tips don’t help or you don’t feel comfortable trying them on your own, we are happy to help! Call (708) 556-2336 or visit our website at

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