Why Is My Thermostat Blinking?

Blinking Thermostat

Most homeowners have a programmable or smart thermostat. This handles setting the temperature for your home. You're familiar with the functions of your thermostat. If it starts to blink at you, this may lead to some alarm. Knowing why this is happening and what to do is vital to make sure that your HVAC system stays working.

Do You Have Low Battery Power?

It's crucial to note that your thermostat will blink for a couple of different reasons. The most common is that your battery is going low. You need to pop off the cover of your thermostat. Here, you can replace the batteries inside of it. The blinking light should go off after replacing your batteries. If it doesn't, the light is indicating another problem.

Outdoor Unit Issues

What happens when you notice a blinking light on your thermostat but your HVAC system is running? It may be a sign that there is a problem with your outdoor unit. Whenever your outdoor unit detects a problem, it will lock itself up. It will show as a blinking light on your thermostat. This is a built-in safety feature to protect the parts of your outdoor unit.

The best way to approach this issue is to shut off your indoor unit for a full minute and then turn it back on. After 10 minutes, your outside unit should be working again. If it isn't, you'll want to call in an HVAC professional. If possible, count the number of blinks that happen in one sequence. Many HVAC systems have programmed codes to reveal what's wrong.

Cool On Mode

At one point or another, you may notice that your thermostat blinks with a "Cool On" message. When this happens, your air conditioning system won't blow any cool air. This means that the temperature in your home is the temperature on your thermostat.

Since your HVAC system doesn't need to produce any more cold air, it creates a time delay. This shuts the compressor off. You can test to make sure that your HVAC system is in delay mode by turning the thermostat down a few degrees. Your unit should kick back on. If it doesn't, it's a sign of a bigger problem. You should have this checked by an HVAC professional.

Contact Us Today


If your thermostat is blinking and you need help, contact our HVAC professionals. They can check your system, inform you of the issue, and fix it.


Contact Ardmore Fresh Air at (847) 792-1019 for your next appointment or any questions regarding our blog articles! In a hurry? Schedule your appointment online now.