14 Reasons Why Your Thermostat Screen Is Blank & What to Do About It

Your thermostat is the brain of your home HVAC system and plays a crucial role in maintaining your optimal home climate. According to the EIA, they are used to control central heating equipment in nearly 85% of households. So, it can come as a shock if you come home one day and find that your thermostat screen is blank and it is not working at all.

However, it’s not necessarily a cause for panic. In fact, many of the causes of a blank thermostat are straightforward and can be quickly resolved with a little troubleshooting.

This blog delves into the common culprits that render your thermostat screen blank and the solutions to revive it so you can get back to enjoying a comfortable home temperature.

1. Thermostat Is Powered Off

When you notice an issue with your thermostat display, it can be frustrating, and you may feel worried about the potential costs of fixing or replacing the device. However, before starting the troubleshooting process, it’s best to stick to the basics – checking the power source. A common reason for a thermostat display not turning on is simply that it was switched off by mistake.

Solution: Turn on your thermostat and check whether the display screen is visible.

2. Dead Thermostat Batteries

If you have a battery-operated thermostat, it will shut down if the batteries have died. When these thermostats are not properly powered, they are unable to send signals to your heating and cooling system and thus display a blank screen. Another sign of low battery power is the fading or flickering of the screen.

Solution: You can easily restore the functionality of your thermostat by replacing the batteries. Consult your user manual for step-by-step instructions on how to remove the old batteries and install new ones. It’s recommended to replace your batteries at least once a year.

Even after battery replacement, if your thermostat isn’t working, you may be using the wrong type of battery. Ensure that you are using the recommended batteries by referring to the manual.

3. Lack of Maintenance

Proper maintenance of your thermostat is crucial for its optimal performance. Dust and debris within the sensitive components of the thermostat can cause electrical and mechanical problems. Dirt particles can block the sensors, leading to inaccurate temperature readings. Dust can also accumulate in the thermostat wires, and can be one of the reasons why your thermostat isn’t working.

Solution: For programmable or mechanical thermostats, it is important to remove the cover (if applicable) or unmount them in order to clean them. It is recommended to use a microfiber cloth or a soft brush to remove any debris gently. Avoid using a wet cloth or wipes, as moisture may cause damage to internal components.

Smart thermostats typically do not require internal cleaning. Simply remove dust from the top of the thermostat using a soft cloth. By regularly cleaning your thermostat, you can ensure smooth operation and contribute to efficient heating and cooling in your home.

4. Tripped Circuit Breaker

One of the common reasons your thermostat screen goes blank is due to a circuit breaker trip. A high-powered appliance sharing that same circuit breaker as your thermostat can cause a power surge. This can trip the breaker, cutting off the power to your thermostat. A faulty circuit breaker can also result in your thermostat going blank.

Solution: Start by examining your circuit breaker. If you notice that it has tripped, try resetting it. The thermostat screen should power back on.

However, if the circuit breaker continues to trip repeatedly, it’s best to avoid resetting it again and instead shut off your HVAC system and thermostat. This will prevent any potential hazards. At this point, it’s important to seek professional assistance.

Related: Air Conditioner Circuit Breaker Keeps Tripping? 10 Possible Causes & How to Prevent Them

5. Damaged Thermostat

Your thermostat can fail to power on due to physical damage. For instance, if you have accidentally knocked it out of the wall, the display will malfunction, and you will notice a blank thermostat screen. It can also result in technical problems.

Solution: Contact a professional to diagnose display issues and fix them.

6. Power Outage

Your thermostat screen can go blank after a power outage. Even after the power is restored, your thermostat may not immediately turn back. This is to prevent damage from a sudden power surge that can take place after electricity returns.

Solution: Resetting your thermostat can help in this case. The thermostat resetting procedure can be different depending on your model. Refer to your manual for instructions. For digital thermostats, you can check if they have a recessed reset button, and for smart thermostats, just pulling them off the wall for 1-2 minutes would work.

Related: Alternative Heat Sources for Power Outages to Keep You Comfortably Warm

7. Short Cycling

If you notice your thermostat goes blank and then comes back, it can be a sign that your unit is short-cycling. The most common reason for that is dirty air filters.

A clogged filter restricts the airflow, which results in the overheating of your system. An overheated system will shut down before completing its cycle.

Other reasons include an improperly sized unit, a refrigerant leak, and a tripped breaker.

Solution: Refer to a professional as soon as possible. Short cycling is a serious issue that can severely impact your HVAC unit.

It’s recommended to change your filters every three months. By regularly maintaining your air filter, you can ensure efficient operation and prevent short cycling problems.

8. Blown Out Fuse

If your thermostat went blank, one of the reasons could be a blown fuse. The fuse conducts current at a certain level, and if it goes above that, it can result in a blown fuse. To verify if this is the case, you will need a multimeter, a device that can assess voltage irregularities when your thermostat display isn’t functioning.

Solution: To begin, locate the fuse box on the exterior wall of your home near the air conditioner unit. Attach the multimeter to each fuse in the fuse box. The multimeter will indicate if any of the fuses are devoid of voltage.

Should you identify a blown fuse, a replacement can easily be obtained from a local hardware store or online. By checking and replacing the blown fuse, you can restore the power to your thermostat and resolve the issue of a blank display.

9. Tripped Safety Switch

Sometimes, when your thermostat is blank and your AC has stopped working, it can be due to the activation of the safety switch.

If your HVAC detects issues like high temperature or excessive moisture level in the system, it can trigger the safety switch. This shuts down your unit and causes the transformer to stop sending voltage to your thermostat. Dirty air filters can also trigger the safety switch, causing your HVAC to shut down.

Solution: Inspect the safety switch, usually located near the drain pan. If you discover that it has been triggered, it is advisable to contact an HVAC professional for a thorough inspection of the system.

10. Thermostat Wiring Issues

Your thermostat connects to your HVAC unit through a set of various wires. If they are not connected to their assigned terminals or if they are attached loosely, it can result in various problems. The loose wiring can disrupt the communication between the device and the HVAC unit, and you will notice a blank thermostat screen. Sometimes, rodents or other pests can chew the wires in the attic or other hidden areas where the wires are passing through.

Solution: To fix these issues, start by turning off the power at the circuit breaker. Next, remove the thermostat and carefully examine the wires. Reattach the wires securely to their terminals. Finally, check for any loose wires and tighten them as necessary. Check out this detailed thermostat wiring guide.

If the wires are chewed or torn, consult a professional, as they will require replacement.

Note: If you’re not comfortable checking the wires yourself, it is advisable to contact a professional HVAC technician.

11. Aging Thermostat

Have you tried all the troubleshooting hacks, but still, your thermostat screen is blank? It may be time for a replacement.

Thermostats have a lifespan of ten years on average. If it has gone past the decade mark, it won’t function like it used to. Aging thermostats can struggle to sense temperature accurately, making it difficult to maintain a comfortable home environment.

Not only that, incorrect temperature readings can also lead to wasted energy as your HVAC system works harder than necessary. Other signs of aging include buttons or touch screen becoming unresponsive.

Solution: Upgrade to a smart thermostat for a more convenient and automated solution. Smart thermostats can maintain your home at the perfect temperature without requiring constant adjustments. Plus, smart thermostats can help you save energy and keep your electricity bills in check.

12. Thermostat Screen Brightness is Too Low

Did you know that some thermostats have adjustable brightness levels? If you’re staring at what appears to be a blank display, it may be because the brightness is set to an extremely low level.

Also, certain thermostats have auto-dimming capabilities. This means that the screen brightness adjusts itself based on the amount of ambient light in the room or during the day.

Solution: Adjust the thermostat display brightness to your preference if they are set too low.

13. HVAC Access Door is Open

The HVAC access door grants technical access to the internal parts when carrying out maintenance tasks. When your unit is operating, it should be kept closed.

Some thermostat models can turn off if the access door is slightly loose or opened. This is a safety feature that prevents potential hazards and damage to your HVAC system.

Solution: Check your access door and close it firmly to fix this issue.

14. Incompatibility Issues

If your thermostat is not working after recently replacing parts of your HVAC or installing a new heat pump or furnace, compatibility issues may be the culprit. In these situations, the new components might not communicate effectively with your thermostat.

Solution: Simply call an HVAC specialist who can assess and address the compatibility problem. When buying a new HVAC system, it’s best to check the compatibility with your thermostat beforehand to avoid this issue.

Troubleshooting a Blank Thermostat Screen

If you ever come across a situation where you end up wondering why is your thermostat screen blank, understand that there can be multiple reasons behind it. The most common ones include dead batteries, power outages, wiring issues, and lack of maintenance. Fortunately, you can fix most of these issues yourself. However, in some instances, such as if your thermostat display is damaged or if the safety switch is triggered, it may be necessary to seek professional assistance. To prevent a blank thermostat screen, change the batteries regularly, keep up with regular maintenance, and properly install your thermostat.

Sometimes, your thermostat screen is blank without any apparent reason. It may have completed its lifespan and requires replacement. When purchasing a new thermostat, it’s recommended to upgrade to a more efficient model, such as a smart thermostat, to fully automate your home climate control.