You’re sitting in front of your computer, and you decide to turn on the air conditioning because it’s hot outside. The AC comes on, but the screen doesn’t work; you can’t even see what temperature you have it set at.
The furnace turns on and off, the lights are still bright, and the sound system still works; everything else on your thermostat seems to be working correctly except the screen itself.
Turn off the Heat
If your thermostat screen is blank but you can hear your fan running, there may be a problem with the wired connection to your thermostat. Check that all wires are tightly connected and reconnect them if necessary.
For some models, all you need to do is reset by pressing or holding down two small buttons on your HVAC control board for several seconds (check your owner’s manual). This should restore power to your thermostat and bring back its display.
If it doesn’t work right away, try again in an hour; these things sometimes take time. If you still have no luck, contact a professional. Your HVAC system may have gone bad during these intermittent power disruptions and will need to be replaced.
Turn Off Power to Central Unit
When central air conditioning isn’t working correctly, there are two things you can do. First, check to make sure your thermostat is set correctly.
If it is and your home isn’t cooling as it should be, turn off the power to your central unit for a few minutes. Wait five minutes, then turn it back on.
Repeat if necessary until your home reaches its desired temperature. This usually fixes minor issues with an older system.
Check Fuses and Breaker Box
Your thermostat’s screen may be blank because of a blown fuse or tripped breaker. Before you can fix that, though, you’ll need to know where your thermostat is located and what circuits and breakers power it.
Most breaker boxes have circuit maps posted nearby. Check there to see if your A/C unit is on a separate circuit from other appliances in your home—you don’t want to accidentally turn off power while you fiddle with wires!
You might also want to consult an electrician or hire a professional if things are too complicated. If nothing else, make sure everyone in your house knows not to flip any switches until you say so.
Replace Batteries in Thermostat Receiver
Before you dive in, check that your thermostat’s batteries are fresh. If they aren’t, they may be causing your screen to go blank.
Most thermostats have a battery drawer on their bottom; simply pop it open and replace any dead batteries with fresh ones (you should use AA alkaline or lithium batteries—don’t use rechargeable).
The front of your remote may also feature a small battery compartment, so check there as well if your receiver is still blank after changing its batteries.
Replace Batteries in Remote Control
If your remote is not working, it’s possible that it just needs new batteries. If your remote has a slide-out battery compartment or screws on, replace those batteries. Test your remote to see if it works with the new batteries in place.
If it still doesn’t work, you may need to replace something else or have an electrician do an inspection on your heating and cooling system for safety reasons.
However, if there are no lights on at all when you try turning on your heating and cooling system with new batteries in place, then there might be a problem with something else entirely and you should schedule maintenance soon.
Reset Remote Control
If your thermostat screen is blank but you can control your HVAC system using your remote, there’s a good chance that you can fix it with a simple reset. This is an easy fix for most models.
If you’re having issues with a thermostat with an LCD screen, many times resetting will solve whatever issue is being experienced by bringing back your home heating and cooling systems to their original factory settings.
First, unplug your HVAC unit from its power source and then remove any batteries that may be present in remotes or keypads (if applicable). Afterward, wait 15 seconds before plugging everything back in. You should then be able to see all of your readings on your screen again as it was originally configured.
Loose Electrical Wiring
Sometimes, you’ll find that loose wiring can cause a screen to show nothing but black and your fan to keep running. If a wire comes loose in your thermostat’s display, it may not send any signals to your home’s cooling and heating systems.
If you notice that your fan is working even though your screen is blank, it’s probably a simple fix—just replace all of the wires in question. This requires only basic electrical skills.
Also read: Arcade Monitor No Picture Issue Solved
A home’s heating and cooling system is a complex mechanism. It’s important to troubleshoot when there are errors since improper functioning can lead to wasted energy, high utility bills, and even an uncomfortable environment.
Luckily, if your thermostat’s screen is blank but fans work, it’s not hard to diagnose and fix. On average, you should expect to spend between $400-and $600 on HVAC repair services.