Why Does My Air Conditioner Keep Turning Off and On? | Air Conditioner Repair in York, PAThere are a few reasons why your air conditioner could keep turning on and off. One of them is that it’s working correctly — we’ll go over that in a moment. But, if it’s happening too often, that’s a sign there’s a problem somewhere. 

We’ll go over the four leading causes for an AC shutting off and kicking on way too often. You can take care of two yourself. The others will require a professional. And, of course, we’ll explain when it’s normal. 

Read: Why Is My Air Conditioner Blowing Hot Air?

In the meantime, call or email us with questions about the system in your York, PA home. We’re happy to walk you through any small items. And, we’re always available for air conditioner service, repairs, replacements, and installations. 

But first, let’s start with how things should work. 

Central Air Conditioners Cycle On and Off

checking thermostat when air conditioenr turns on and off too muchYour conventional central air conditioning system should not run all the time. The way it works is that the thermostat tracks when temperature drifts from the setting you put into it. 

When it gets a few degrees warmer, the thermostat tells the AC to turn on. Then, it will run until it’s a few degrees cooler than how you want it. It overshoots so that it doesn’t need to turn on the cooling system again right away. The longer it takes to get too hot, the less often you’re using it. 

That’s why it’s natural to hear the system click on and off, maybe four or five times an hour, for a few minutes each time. But, it shouldn’t turn off again in a few seconds. And, you shouldn’t notice it turning on and off more often than every 10 or 15 minutes. 

This process is called “short-cycling.” It’s a sign of a problem, and if you leave it alone, your system can break down years before it should. That happens not only because you’re letting a problem get worse. Over time, all that extra wear and tear takes a massive toll on the moving parts in your AC. 

Fortunately, we can help you head off these problems. 
Read: Why Won’t My Central Air Turn On?

Four Reasons Your AC Keeps Turning On and Off

If your central air is short-cycling, or turning on and off way too often, check for these four possible causes:

  • The Air Filter is Clogged
  • Your Thermostat is Broken
  • Air Conditioner is Too Weak
  • Air Conditioner is Too Strong

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The Air Filter is Clogged

dirty HVAC air filter vs clean filterStart by checking your air filter — that small screen you should replace every month, or at least once per season. Its job is to block debris, dirt, dust, and other contaminants from passing through your system, building up in the ductwork, and coming through the vents

But if you don’t change it often enough, it gets clogged. All the stuff it catches builds up until not even air can pass through the system. Eventually, it causes the system to short-cycle. It’s more of a problem in the winter, but it can cause AC problems, too. 

When the air can’t get past the filter, it builds up where it shouldn’t. Eventually, your system detects the pressure and recognizes it as something wrong. So, it turns off as a failsafe. In the winter, the excess heat can cause a carbon monoxide leak, so it shuts down quickly. 

This problem puts you in a loop: The thermostat turns on the system because it’s too hot. The system shuts off right away because it’s not working properly. But it’s still too hot, so the thermostat tells it to turn back on. 

Change your filter, and if it’s grey or darker, you know it’s clogged. 

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Your Thermostat is Broken

Your thermostat also could be causing this problem by giving the wrong signals to your system. The reason could be anything from a short somewhere that causes it to turn on and off way too often. Or, it’s no longer reading the temperature correctly. 

Use a separate thermometer to check for this. Hold it up to the thermostat. Are the readings the same? If not, there’s a problem. Depending on what kind you have, it may be cheaper just to buy a new one. Or, call an HVAC contractor if you have a more expensive smart model. 

Next, try setting the thermostat to be way too cold, or hotter than you want. Compare the temperature in the room with your separate thermometer to when the system clicks on or off. If it’s not matching the settings, you’ve likely found the problem. 

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Air Conditioner is Too Weak

If your air conditioner is undersized or too weak for your home, it will run way too often. This problem is straightforward, but it also points to a similar, less obvious problem. We’ll get to that one in a moment. 

For now: There’s a chance that whoever installed your AC didn’t do a proper load calculation. As a result, your system isn’t strong enough to keep the house cool. That’s why thermostat keeps turning it on again and again: The temperature is never quite right. 

Short of replacing it, the only thing you can do is set it lower than you’d like. Then, use fans or other methods to stay cool. But, the more you run it, the more you’ll wear it down, and eventually, it’ll go down for good on its own. 

The other problem, however, is if:

Air Conditioner is Too Strong

Bigger’s always better, right? Well, not when it comes to HVAC systems. When your air conditioner’s too strong for the house, you run into the same problems with an undersized system: Short-cycling, uncomfortable temperatures, and premature breakdowns. 

Here’s the problem: It technically works too well. An oversized system sends a strong blast of cold air through the vents. That creates a quick, drastic drop in temperature, enough for the thermostat to shut if back off right away. But that’s not how it’s supposed to work. 

Instead, you want a steadier stream of cooling. This helps maintain the temperature you want. Otherwise, that cool air just dissipates without really doing the job. Plus, you want the AC on more often to help dehumidify. When the system short-cycles, it leaves the air too humid. 

As a result, the temperature creeps back up quickly. The AC goes back on, but just for a few moments, and the cycle repeats. 

Again, unfortunately, the best option is usually replacement. In some instances, we can extend the ductwork so that the airflow isn’t too strong. But, that can easily cost you over a thousand dollars. At that point, you may as well just replace the system. 

Air Conditioner Repairs in York, PA

Don’t wait until a small problem with your air conditioner gets bigger before you call for repairs. The sooner you call us at Air Comfort Technologies, the sooner we can get your York, PA, home comfortable again. If we nip a small problem in the bud, you can end up paying much less for repairs than for a full AC replacement.

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