Blank Thermostat Display

Is your home’s thermostat screen blank? A blank thermostat display can be a major problem, especially during cold winters or hot summers, since you need your thermostat to operate your AC system.

But don’t panic, there could be a quick and easy solution!

If you recently noticed that your thermostat is blank and not working, then the most likely culprit is either the thermostat was switched OFF or the batteries died. Replace the batteries and try to switch the thermostat to ON.

Still not working? Check out this guide and discover some of the most common causes of a blank thermostat display and what you can do to fix the issue.

10 Reasons Your Thermostat Screen is Blank

Follow this troubleshooting guide to fix a blank thermostat screen.

1. Thermostat is Off

Before getting into more technical troubleshooting, double check that the thermostat is turned ON. Unless you live by yourself, there’s always a possibility that someone turned it off on accident or on purpose to turn off the AC.

2. Dead Batteries

The first thing homeowners should do is replace the thermostat’s batteries. Even if there is still some power in the batteries, dying batteries could result in intermittent power to your thermostat. So if your thermostat goes blank and then comes back on, try putting in fresh batteries and seeing if that fixes your issue.

Most thermostats will display an indication for low battery levels or emit a low beeping sound every now and then. Depending on the type of thermostat you have in your home and the batteries you use, you may only need to replace them every couple of years. Others might need to change their batteries every few months.

3. Tripped High-Limit Switch

If your thermostat screen goes blank after several minutes of operation, it could be due to the high-limit switch tripping.

Most furnaces have a high-limit switch that prevents the system from overheating. Overheating typically occurs due to poor airflow or parts that are going bad or broken.

4. Low Display Brightness

If your thermostat allows you to change the brightness level, be sure to check that the brightness isn’t turned down. Some thermostats will also auto-dim the screen at certain times of the day or when there is too much light around it.

5. Furnace Door is Open

Some thermostats, particularly Honeywell thermostats, will go blank if the furnace door isn’t completely closed. Ensure that your furnace door is not ajar and is closed securely and see if that fixes the problem.

6. Tripped Breaker

Modern programmable thermostats, including those with wireless capabilities, are generally connected to the home’s main electrical system. If the breaker trips then it will shut off power to your thermostat and if there’s no battery backup, the screen will go blank.

If there was recently a power surge in your home or you’ve been running multiple appliances at the same time, this may be your problem.

Every homeowner should know where their electrical box is and how to turn the entire system off and on in the event of an emergency. Reset the circuit breaker and see if the screen turns on. If the screen is still blank, then it might be time to replace the thermostat entirely.

7. Tripped Float Switch

Most new furnaces and air conditioners have safety sensors, sometimes called a float switch, wired to the thermostat. If the sensor detects high moisture, it will turn the system off.

In many instances, these safety switches misread their surroundings and simply need to be reset, but it could also indicate that you have a clogged AC drain line.

8. Wiring Problems

Your thermostat has many electrical connections that serve various functions from the screen display to allowing your thermostat to communicate with your HVAC system. If you recently had a thermostat installed or installed it yourself, this may be your problem.

Unless you have an electrical background and know what you’re doing, we don’t recommend attempting to fix loose connections or wiring problems yourself.

9. Blown Fuse

Some thermostats have a fuse inside for extra protection from power surges. If the fuse is blown, your thermostat won’t work properly and you’ll have to replace the fuse.

10. Your Thermostat Needs to be Replaced

If none of the above fixes your issues then your thermostat might need to be replaced. The average life expectancy of a thermostat is around 10 years, but this number varies based on your specific model.

If your thermostat is more than 10 years old, it may be time to upgrade. Contact a local HVAC company to see if your thermostat can be repaired or needs to be replaced.