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12 Reasons Why Your Thermostat Is Blank

You wake up and your thermostat is blank! What do you do? A blank thermostat can be frustrating; what are you even supposed to do? If your thermostat is blank, there are some very simple causes with even simpler solutions that you can try.

But unfortunately, it may be a sign of a more serious issue. Millian Aire AC & Heating is here to help get this problem resolved if you are experiencing it. Be sure to give us a call now – (727) 233-5566

Why Is My Thermostat Display Blank?

Thermostat is blank and Millian Aire technician is fixing it

The most common reason for a blank thermostat is an issue with the power supply. This may be a dead battery, a tripped breaker, or a blown fuse. It may be related to the wiring, display settings, or it may be that your thermostat is damaged or old and needs to be replaced or upgraded.

Luckily, identifying fixable issues related to your AC thermostat display is pretty straightforward. Since it’s important to consider every simple DIY solution before shelling out cash for a professional, you will need to consider the problem from all angles. Keep reading for an in-depth review of all the possible reasons that your AC display is blank.

Thermostat Is Off

Sometimes, an issue with your thermostat display appearing blank is as simple as turning the thermostat on. Maybe it was switched off accidentally or maybe a power surge caused it to reset. Either way, you should be able to locate a switch or a button on the thermostat itself to turn it back on. If you have a smart thermostat, you may be able to turn the power back on through the app.

If it doesn’t turn on, you will need to check other power-related issues like dead batteries or circuit breakers.

Dead Batteries

Some older thermostats may still run on batteries, but not all thermostats run on batteries. This is especially true if you have a smart or wifi HVAC system. These can, of course, drain over time. This is especially true during hot Florida summers when you are more likely to run your AC and fiddle with the settings.

There’s likely a compartment along the side of your thermostat that houses batteries. You will likely need regular AA or AAA batteries, a button-style lithium, or a 9-volt battery.

If switching out the batteries turns your thermostat back on, you may want to mark your calendar and plan on replacing the batteries once a year to prevent these issues in the future.

Screen Display Brightness Level

This is another simple fix. The brightness level on your thermostat’s display may not be set appropriately. This is especially true in bright and sunny Tampa, where the sun can easily wash out the display on your thermostat.

If you have a smart thermostat, you can check the display settings in the app. If not, you will likely need to consult your user manual and attempt to adjust the settings “blind” since the display is blank.

Tripped Circuit Breaker

A tripped circuit breaker can turn off the power to your thermostat. Breakers usually trip because of overloaded circuits or a short in the system. Depending on your house’s wiring, it may be the only appliance associated with that particular breaker, making this issue harder to identify.

Check your home’s circuit break and reset any tipped breakers.

If this issue happens often, you should get an electrician out right away, as this may be a sign of a more serious electrical issue.

Dirty Air Filter

While it may seem like a simple and unlikely culprit, your thermostat may be blank because it shut off due to a dirty, clogged air filter. A clogged air filter will make your AC unit work less efficiently. Over time, the extra stress can overload or overheat your AC unit and cause it to shut down. 

Replace or clean your air filter, depending on what type you have. If this gets your AC back up and running and your thermostat turns back on, then that may have been the problem.

It’s important to regularly replace your air filter. Not only will this keep your AC unit from overworking, but it ensures your home is being conditioned with clean, fresh air.

If you are wondering, “How often should I change my air filter?” – the answer varies. At Millian Aire AC & Heating we recommend replacing your air filter every 30 days.

Triggered Safety Switch

Most HVAC systems have a high-limit switch and a temperature-limit switch. These safety mechanisms engage and shut off the system in case of water leaks or if the temperature gets too high, respectively.

Check for any water leaks, blockages, or other issues with your HVAC system. It’s important not to reset the safety switch until you have identified and fixed the issue that triggered it in the first place.

You will need to give Millian Aire a call so we can look over your system to see what is going on.

Wiring Issues

Loose or corroded wires can disrupt the power supply to the thermostat, causing the screen to go blank. To check out your thermostat’s wiring, turn off the power to your thermostat at your breaker box.

If you are comfortable with taking your thermostat off the wall, you may be able to see if there is a loose connection. Sometimes taking the thermostat off the wall and putting it back on will resolve any loose connections.

If you do not see anything obvious, you can always give us a call.

Dirty Wiring

Dust and debris can accumulate over time on and in the thermostat. This can cause electrical shorts or other malfunctions in the thermostat. So, while you have your thermostat open, if nothing looks damaged, start by gently cleaning the unit with a pressurized air canister. Be very careful not to dislodge or damage any of the internal parts.

Reinstall the thermostat and turn the power back on. If your cleaning was effective, your thermostat should turn right back on. Never use water or any kind of liquid as this will damage your unit.

Blown Fuse

The most common cause of a blown fuse is a refrigerant leak. A refrigerant leak can cause your AC to work harder to reach the set temperature, which can cause an internal fuse to break.

Replacing a blown fuse is as simple as locating the fuse inside of the thermostat and replacing it with a new, matching fuse. 

However, the fuse likely blew for an underlying reason. Your best bet is to call Millian Aire and get your system thoroughly inspected.

Mismatched Parts

Sometimes, a thermostat and an HVAC system are simply not compatible. If you’ve recently upgraded your thermostat to a smart or Wi-Fi-based thermostat but didn’t upgrade your HVAC unit, you may have compatibility issues.

Double-check your user manuals to make sure that your thermostat is compatible with your HVAC system. If not, you might need to replace either the thermostat or upgrade your HVAC system.

The Thermostat Needs to be Replaced

Like all technology, thermostats don’t last forever. Modern thermostats typically have about a 10-year lifespan. If you have an older thermostat with a blank display, it may just be time to replace it. Modern thermostats offer more features and conveniences like controlling your indoor temperature from your smart phone.

Make Sure the HVAC Access Door Isn’t Open

HVAC systems have various access doors and panels for techs to get to the internal parts. Many brands install safety features so that the system cannot run while these doors are open.

Check your HVAC access panels around your ductwork and furnace to make sure they are all closed. If they are even slightly open, your AC system may not be receiving power, and your thermostat will be blank.

Getting Your AC Thermostat Displaying Again

A Millian Aire technician turning on a new thermostat

A lot of things can cause a blank thermostat screen, with fixes ranging from simply changing the batteries to more complex problems like wiring issues. If you are uncomfortable or unfamiliar with electrical systems, it’s always best to consult a professional.

Give us a call at (727) 233-5566 or book a service directly online. Regular maintenance of your HVAC system and thermostat can prevent many of these issues, so check out our “Millian Aire Club” where you can get routine maintenance without all of the hassles. Remember, a well-functioning thermostat is key to a comfy and efficient home.

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