Is Too Much Refrigerant in Your AC a Problem?

D.P. Taylor
Written by D.P. Taylor
Updated December 28, 2021
air conditioning heat pump outside of home
Photo: Christian Delbert / Adobe Srock


  • Too much refrigerant could lead to a failed AC unit

  • Only certified HVAC pros should tinker with refrigerant levels

  • Signs of an overcharged AC unit are automatic shut downs, squealing noises, and high energy bills

  • Call in a professional to check your refrigerant levels and dispose of excess liquids

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It seems odd to say that too much refrigerant will make your AC go caput. After all, it’s the refrigerant that cools everything down! Sadly, your unit may be in for some trouble if you suspect there’s too much refrigerant in your air conditioner (also referred to as an overcharged AC system).

In its simplest terms, refrigerant works by repeatedly transitioning between a liquid and gas state to absorb heat from indoor air and spit it back out as cold air. But when there’s too much refrigerant flowing inside the copper coils, the system won’t run properly. Keep reading to learn why an overcharged AC system is a problem and what to do when it happens.

How Does an AC Get Too Much Refrigerant?

Frankly, an AC system can become overcharged with refrigerant when amateurs tinker with it rather than hiring a professional. It’s easy for someone to put too much refrigerant into your AC if they don’t have the professional qualifications to properly install or repair HVAC systems. Your technician may have also oversold you more refrigerant than your system can handle. 

The Consequences of an Overcharged Air Conditioner

An overcharged air conditioning system will decrease its efficiency and capacity to cool. It would be the equivalent of a 3-ton system operating at the capacity of a 2-ton system. When cooling demand is at its highest, your AC likely won’t be able to meet it. Depending on how overcharged the system is, it may stop cooling altogether.


"Slugging" is when too much refrigerant gets into the compressor while it’s in a liquid state. Slugging can break valves, connecting rods, and the compressor itself. The worst-case scenario? Too much refrigerant could cause total burnout of the motor itself, ultimately destroying your AC system.

Excess Pressure

Because of too much pressure from the refrigerant, the AC unit won't run as efficiently and won't cool your home as well.

How Do You Know If Your Refrigerant Is Overcharged?

If you suspect your AC unit isn’t working properly, check for these four main signs that indicate an overcharged AC system.

Automatically Shutting Down

Many AC units have safety switches that will automatically shut down the unit if it detects too much refrigerant. You’ll probably need to call in a local HVAC professional to get it running again if this happens.

High-Pitched Noises

Your unit will make a squealing sound if a pro sprays too much refrigerant liquid through the compressor. The high-pitched noise indicates high pressure, which will break your system if left untreated. 

Blowing Hot Air

An overcharged AC unit may start blowing hot air because the motors have to work extra hard to handle all the refrigerant inside the coils.

Higher Energy Bills

These issues add up to a poorly functioning AC unit, as it is working harder to cool air efficiently. You’ll know this is the case when your energy bills spike. 

How Do You Fix an Overcharged AC?

electrician working on refrigerant on ac
Photo: kuchina / Adobe Stock

Contact an HVAC professional near you to get levels down to a recommended level. You should not attempt to fix a refrigerant problem yourself for two reasons:

  • It is against the law to DIY refrigerants. The Environmental Protection Agency mandates that only licensed, EPA-certified professionals can handle or dispose of refrigerant.

  • It is a dangerous liquid. This ingredient is toxic, highly flammable, and dangerous to your health.

  • It will cause more problems: An overcharged AC system is usually the result of an amateur or DIY attempt. Instead, leave refrigerant levels to the professionals.

A professional can come to your home, measure your current levels, estimate any necessary repair work, and provide you with a quote. That way, you can ensure that a pro will get the job done safely and by law so your unit sticks around for years to come.

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