AC RUNS CONSTANTLY: TROUBLESHOOTING AND DIY FIXES


What to do if your AC runs constantly.

18 Aug, 2021

The sound of an air conditioner running constantly isn’t just a concern because it’s annoying. 

It could mean you’ve got a problem with your unit—a problem which could be exacerbated by the wear and tear of it constantly running. 

And let’s not forget the load on your electricity. An air conditioner running all day is not going to be friendly to your electric bill. 

Your AC requires regular maintenance to function effectively and efficiently, but as with all appliances, it’s susceptible to break downs from time to time. 

Is this the case with your AC running constantly, or is it normal? 

Here’s a guide to help you get to the bottom of this situation, along with possible DIY fixes and hints on when it is time to call a professional

Is It Normal For My AC to Run Constantly? 

Sometimes it can be so hot outside that your AC needs to run constantly to reach the set temperature. 

An air conditioner will usually run cooling cycles of around 15-minutes on a typical summer day. If this sounds familiar, your AC is most likely doing its job as it should. 

You should be concerned if: 

  • Its cooling cycles last 30 minutes to an hour. 
  • Your AC runs constantly all day without shutting off or cycling on and off.
  • Your AC does not stop running even when the set temperature is reached. The room may even be freezing cold.   
  • It’s been running nonstop, but the room has not cooled more than a degree or two all day. 
  • Your air conditioner keeps running when turned off. 

If any of the above points describe your situation, you most likely have a problem with your system. 

AC Runs Constantly? Common Causes 

Let’s take a look at some of the common reasons you have an air conditioner running non stop when it shouldn’t be. 

1. Your AC is Too Small 

This problem usually occurs if you’ve recently renovated your space and changed your layout or even just changed your AC unit.  

Bigger is not always better when choosing a new air conditioner, but small can be just as bad, if not worse. 

Air conditioners that are too small for your home are highly inefficient. If your ac runs constantly and struggles to keep the room cool on hot days, it may not be the right size for your space. 

To confirm, check if the air from the vents is cool and the airflow normal. A too-small AC runs normally but doesn’t cool your home to the set thermostat temperature, especially on hot days.  

How to fix the problem

Your best bet is to contact a certified HVAC professional to look at the size of your home and do a load calculation. Measured in tonnes, the size of your air conditioner should take into account the design, size, and cooling needs of your home. 

2. A Faulty Thermostat 

You’ve picked the perfect thermostat setting for your home, yet it seems like your central air keeps running with no change to your home’s temperature? 

A quick search of “AC running constantly does not shut off when set temp reached” will tell you that your thermostat may be the culprit. 

Thermostats are typically reliable, but problems such as weakened batteries or loose wires can cause them to malfunction or not work at all. 

Sometimes it can be as obvious as your AC running even if the room is freezing cold. Other times it may take a bit more to diagnose it: Place a thermometer near your thermostat and check the reading after an hour or two. If your home is at the desired temperature, but your AC stays on, you have a thermostat problem on your hands. 

How to fix the problem

A few basic steps you can do yourself include: 

  • Checking that the thermostat is correctly set to “cool.” 
  • Ensuring there is power feeding the thermostat by checking its wiring supply or replacing its batteries. 
  • Dusting off any dirt or debris that may have collected in and around any parts of the thermostat. 
  • Replacing the thermostat altogether. 

Always turn off the power to the thermostat before doing any investigation or fixes. 

3. Reduced Airflow 

If you have your AC running all day but it doesn’t supply your home with enough cool air to reach the set temperature, it might be due to reduced or restricted airflow. 

Your unit’s blow might have a problem or be blocked by things such as dirt and debris. 

Similarly, clogged ducts, coils, and air filters are likely to be the cause of airflow problems and inefficient cycling. These problems may even be the reason your outside AC unit runs constantly.

How to fix the problem

Start by inspecting the following for dirt, debris, or damage: 

  • Air vents 
  • Air filter 
  • The unit’s ductwork 
  • The evaporator and/or condenser coil 

You can easily clean your air conditioner to help the system dispense cool air more efficiently. 

However, the problem may be caused by something less obvious, in which case you should contact a professional to diagnose the problem. A regular maintenance run from your HVAC specialist could be all your unit needs. 

4. Low Refrigerant 

This is a common cause of a constantly running AC. 

A low refrigerant level means your air conditioner isn’t blowing any cool air and thus not reaching your set temperature level. 

How to fix the problem

Call your AC contractor to check the unit’s refrigerant levels. If your AC was recently serviced, this might be an indication of a refrigerant leak, which your repair professional should look out for. 

5. Your AC Needs to Be Replaced 

It might be time for a replacement if you find that your air conditioner constantly malfunctions, e.g, the air conditioner keeps running when turned off, or does not go on at all. 

Call the Experts 

A reliable and efficient cooling system is a must-have for the comfort of any home, so it’s an urgent matter if your AC runs constantly when it’s not supposed to. 

Valley Service is your most trusted option for fast, quick, and easy HVAC AC service. We offer repair and maintenance of just about every make and model available. 

Call us today to have one of our HVAC technicians fix your unit right away.