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Why Is My Home’s AC Running Constantly? A Minneapolis-St. Paul Tech Answers

Why Is My Home’s AC Running Constantly? A Minneapolis-St. Paul Tech Answers

It’s normal for your air conditioner to run longer on hot days, but if you notice that it runs non-stop regardless of the outside temperature, then you have a problem.

Your AC may be running constantly because of one of these common AC problems:

  1. The thermostat is on the wrong setting
  2. A clogged air filter
  3. Blocked or dirty outdoor unit
  4. Leaking refrigerant lines
  5. Dirty evaporator coil
  6. AC is too old

In this article, we’ll start by sharing the issues you can fix by yourself and then cover when you’ll need to contact a pro.

Live in the Minneapolis-St. Paul area? Need an AC repair? Schedule an appointment today.

AC problems you can fix yourself

Try troubleshooting these 3 issues first. If you can’t fix these, then move on to the next section.

#1: Your thermostat is on the wrong setting

The ON/AUTO setting on a thermostat

What do we mean by the “wrong” setting? Well we mean that your thermostat is set to ON instead of AUTO.

Here’s the difference: When your thermostat is set to ON, it sends the signal to your AC blower to run non-stop. On the other hand, when your thermostat is set to AUTO, it sends the signal to your AC blower to run only as needed.

In most cases (with the exception of cleaning), it’s always best to leave your AC set to AUTO because it uses less energy.

Solution: Check your thermostat and make sure it’s set to AUTO instead of ON.

#2: You have a clogged air filter

Clean air filter vs. dirty air filter

If you have a clogged air filter, your AC system will run non-stop.

You see, your AC system needs to “breathe” in air to cool. And since all air passes through your system’s air filter, if that filter is clogged, then air can’t enter in the AC’s system.

So, to compensate, your air conditioner will run longer to bring in more air.

Solution: Check your air filter. If it looks dirty like the one in the image above, then you should change it.

#3: Your outdoor unit is blocked or dirty


Condenser coils located in the outdoor unit of your AC system

Your outdoor unit works like a heat sponge—it “dumps” out heat collected by the refrigerant in the indoor unit (read: how an air conditioner works).

The outdoor unit releases this heat via condenser coils. (The condenser coils are the little fins that look like this).

If sticks or debris are covering your outdoor unit, then your system can’t dump as much heat. To compensate, your AC will run longer to dump all that warm air outside.

A dirty outdoor (condenser) unit

Solution: Clear any debris from your outdoor unit. Also makes sure that all shrubbery, trees and fences are at least 3 feet away from the outdoor unit.

Note: If you notice that the condenser coils are covered in a thick layer of dust, contact a professional to clean them for you. These coils are delicate, so you’ll want to have a trained professional handle and clean them.

When you need to call a pro

If you think you have one of the following problems, you’ll need to call a professional for help.

#1: Leaking refrigerant lines

Refrigerant is the liquid/gas that absorbs the heat from your home’s warm air. If your AC system is low on refrigerant (because there’s a leak), then your AC will take longer to cool your home.

Signs you have this problem include:

For more information, read our article, “How to Tell if Your Air Conditioner Needs More Refrigerant (Freon).”

#2: Dirty evaporator coil


Where the evaporator coils is located in an AC system

The evaporator coil is the part of your AC system where the refrigerant absorbs warm air and turns it into cold air.

But if the coils are dirty, then the refrigerant has a harder time absorbing the heat from the warm air, which means your AC will run longer to cool your home.

The evaporator coil is very fragile, so it should only be cleaned by a trained professional.

Signs you have this problem include:

  • Musty or moldy smells
  • Reduced cold air from your vents
  • Other parts of your system are breaking down (when fan motors and the compressor try to compensate for the dirty evaporator coil, they work harder which means they have a greater risk of breaking down).

#3: Your AC is too old

Is your AC over 10 years old? If so, that could explain why your AC is running non-stop.

Like any machine with moving parts, air conditioners wear down over time. As components lose efficiency, they take longer to do their job. So it may be time to replace your AC altogether.

Signs you have this problem include:

  • Your AC is 10+ years old
  • You’ve noticed higher energy bills recently
  • Your AC needs frequent repairs

For more information about replacing an old AC, read these related articles:

Need an AC repair in the twin cities?

Just contact us.

We’ll send one of our trained and trusted techs to give you an honest and fair quote on an AC repair.

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Categories: Air Conditioning