Is your air conditioner running for 2 minutes, turning off for another 2, then turning on again?
This is called short cycling. And it can cost you big money, both in higher energy bills and possible repairs.
We're going to be honest with you: this problem could be caused by a LOT of different things. So, it's difficult to troubleshoot without seeing and hearing the problem.
However, we'll go through some of the most common causes.
Bad thermostat placement (or a bad thermostat)
Your thermostat should be placed in a central location, away from windows and air vents.
A thermostat that is near an air vent can be tricked into thinking your home is cool because it senses the cool air blowing over it.
Similarly, one near a window may turn on frequently because the sun heats up the surrounding area, making the thermostat think your home is warmer than it really is.
The culprit could also be a bad thermostat.
A dirty air filters
If it seems like this is a possible problem in almost every article we write, it's because it is one of the most common causes of AC problems.
In this case, a dirty filter can restrict airflow to your air conditioner to the point where your coils freeze up. This would cause the air conditioner to shut off prematurely (before it had finished cooling your home to your set temperature).
Then, a few minutes later, your thermostat will turn your air conditioner on again and the cycle will continue.
Your air conditioner could be low on refrigerant. Similar to a dirty air filter, this will cause your coils to freeze and the air conditioner to turn on and off for short intervals.
Related: Why is my air conditioner frozen?
Important note: If an air conditioning company determines this is the cause, don't let them simply 'top off' your air conditioner with more refrigerant. Refrigerant isn't 'used up' like gas in a car. It is constantly re-used. So, if you're low on refrigerant, you have a leak that needs to be fixed. Otherwise, you'll have the same problem again later.
Dirty condenser coils
If you haven't had regular AC maintenance, the short cycling could be caused by dirty condenser coils.
These coils are in the outside unit of your air conditioner and are responsible for dissipating the heat from your home to the outside air. When they get dirty, their job gets harder. And as your air conditioner struggles, it can overheat and shut off.
An air conditioner that's too big for your home
If you've always had this problem, or it just started when you got a new air conditioning system, it could be that the AC system you installed is too big.
An oversized air conditioner will quickly cool your home and then shut off. While this might seem like a good thing (it only takes 2 minutes to cool your home off!), this can increase your energy bills and lead to uneven cooling in your home.
Here's more about why the right size AC is important.