As a homeowner, a blank thermostat may appear ominous, especially when you want to make temperature adjustments. Luckily, if your thermostat is showing a blank screen, there are several common causes — many you can troubleshoot yourself — to get your system up and running again.
Not sure why your thermostat went blank? Several common causes can impact how the display looks and your system works.
Check out 12 reasons why your thermostat could be blank.
Even though this may seem obvious, one of the first things you should do is check that your thermostat is turned on. It’s possible that someone else in your home turned off the system and didn’t mention it. If the thermostat is turned off by mistake, the screen will be blank.
Simply switching the system back on will cause the display screen to illuminate.
Many thermostats use AA or AAA batteries to power the display. The batteries also provide backup power if you experience a power outage. While the lifespan of batteries can vary, it’s probably safe to change them annually. If it’s been a while since you’ve replaced the batteries, that could be the culprit behind your system’s blank screen.
To troubleshoot, check your thermostat for a “Lo Batt” alert or a flashing battery icon. This signal could indicate that the thermostat batteries are either low or dead. If this is the case, replace them with the same type and size batteries and ensure they are properly inserted.
Whether caused by a short circuit or storm, a power outage can impact your home’s thermostat. If power is unable to reach your thermostat, it won’t be able to operate as it should. You can quicky troubleshoot by checking other lights and appliances in your home to see if they are also out. If they are, a power outage is causing your blank screen.
You may either need to reset any tripped breakers or wait for the power to be restored so your screen can illuminate and function normally again.
Factors ranging from how many pets you have to how often you use your AC can influence how frequently you should change out your AC filter. While the frequency can vary from one home to the next, inspecting and changing it every one to three months is usually recommended.
Over time, dust, dirt and pet dander can clog the air filter, causing the unit to shut down. If this happens, the screen will appear blank.
Another common culprit is loose wiring or other wiring issue underneath the thermostat. Wiring problems could be caused by anything from a faulty wire hooked up to the thermostat to rodents chewing on the wiring and causing damage. No matter the cause, if you suspect a wiring issue, it’s best to reach out to a professional. Working with electricity can be dangerous if you don’t have the proper training and experience to diagnose and repair the problem.
If your thermostat goes blank, there may be a blown fuse. Fuses are designed to help protect your thermostat if an electrical issue occurs. A blown fuse could be caused by a broken filament or a power surge. No matter the cause, use a multimeter device to check the voltage and see if there is a blown fuse. If there is, replacing the fuse should restore power and function to the display.
Sometimes, incompatible parts can cause issues with the display. Schedule a visit with an HVAC professional to ensure the new parts are working properly and are designed for your entire system.
Your thermostat is likely connected to your home’s main electrical system. If the circuit breaker that powers your system and thermostat trips, it will cut off electricity to the thermostat and cause the screen to go blank. You can trip the circuit breaker if you use too many appliances at one time or experience a power surge.
Reset the breaker by switching it to “Off” and then back to the “On” position. This action should then cause the display screen to come back on.
Just like the breaker, the AC safety switch could also potentially trip. The safety switch can detect problems within the system, such as the equipment temperature being too high. If these built-in safety switches trip, the transformer may stop the power to the thermostat. If this is the case, a professional can come out and diagnose the issue and make any necessary repairs.
Issues with the AC and heating system itself can contribute to a blank screen. You can start by first checking the condensate safety switch, which is typically located in the drain pan. If this switch detects any issues, like excess moisture, it could turn the system off, resulting in a blank screen.
If the wiring is dirty or damaged, it can prevent the power from reaching the thermostat, contributing to power issues within the system. To see if these issues could be causing your blank screen, first remove the thermostat’s cover. Brush away any dust that you see inside and look over the wiring. If any of the wires look frayed or torn, they are likely keeping the power from reaching the thermostat, resulting in a blank screen.
If you’ve performed several troubleshooting steps and your thermostat still isn’t working, it may be time to replace it. Your thermostat can fail due to anything from technical problems to damage. While many issues can be repaired, if the thermostat is too old, it may be more cost-effective to replace it instead. A new thermostat will allow you to take advantage of newer technologies to help your system run more efficiently.
No matter what issues you may be dealing with, if you’re looking for an expert to fix your blank thermostat, turn to Zimmerman. Since our founding in 1980, we’ve provided professional home comfort solutions to the Greater Harrisburg area.
Our technicians, who have been factory trained and received NATE certification, specialize in HVAC services, such as maintenance, installation and repair, and are committed to ensuring your installation or repair gets done right the first time. Our experts understand how to quickly assess your system and deliver the right services — that fit your needs and budget.
Reach out today to learn more about our services and request an estimate.
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