AC Overcharging: Potential Consequences and How to Avoid Them

We’ve all been there – your AC is low on refrigerant and it is not cooling the air enough, so you decide to add a bit more refrigerant to the system, and then – yikes – you overcharge it.

Overcharging your AC will cause your air conditioner to blow out hot air or even worse, shut down altogether because it will cause the entire system to overwork. That can lead to permanent damage to your air conditioner.

In this article, I will go over how you can tell if your air conditioner has been overcharged and what the consequences of that may be. I’ll also point out how you can avoid that situation altogether.

Signs You’ve Overcharged Your AC

When your air conditioner pulls in warm air from the inside of your house, it passes it over the evaporator coil that is filled with liquid refrigerant inside which will absorb the heat from the air. 

So having too little refrigerant in your system will impede the cooling process. But having too much could lead to a whole list of problems for your AC.

It isn’t hard to overcharge your AC when attempting to charge it yourself. Especially because the home charging cans that you find at the retail stores don’t always have the best pressure gauges and you might unknowingly put too much in.

The best way to determine if you have overcharged your AC is to have a professional come out and measure the pressure of the refrigerant. They will have the proper tools to measure the levels needed and the levels you have.

But if you notice any of the things below happening, it could be your first sign that you have an overcharged AC.

A lot of frost

Frost on your evaporator coil or any other part of your air conditioner, is never a good thing. But since there are many things that can cause this, it can be hard to decipher the cause. Too little refrigerant can cause ice to form around the coils and too much can also do the same! Frost can also happen due to a dirty filter or a clogged drain pipe.

Ice build up in your AC Unit

So if you find frost or ice on your air conditioner, I would suggest trying to figure out what is causing it first. If you can rule out other obvious possibilities like a dirty filter, and you recently tried to add refrigerant to your AC, check your refrigerant levels to see if your system is overcharged.

It’s producing hot air

If hot air is blowing out of your AC condenser unit, it’s usually because the system is being overworked. This could also, like the problem with frost, be due to clogged ducts, dirty filters, or overcharged refrigerant.

But if you notice the problem right after your routine maintenance check, ask the HVAC specialist if they added any refrigerant. If they did, they might have overcharged it. 

If they overcharged it, there may be too much pressure in the coils which will actually produce heat and cause your AC to blow out hot air.

Loud noises come from your AC unit

If you have overcharged your AC, the excess liquid refrigerant may leak down into the compressor and cause it to vibrate. That could cause a pretty annoying buzzing sound coming from your unit.

But if you have refrigerant leaking down into the compressor, a buzzing noise will soon be the least of your worries. If you don’t fix it right away, it could cause long-term damage to your compressor.

Or your AC may also make a loud squealing noise when it’s overcharged. This can be quite alarming and is probably due to the increased pressure in the coil. Turn off your AC and get it looked at if you hear this squealing. 

Uneven pressure

Uneven pressure levels in your AC are the most definite way to tell if your AC is overcharged. But changes are, you don’t have the right equipment to measure the pressure levels. So in this case you would need to call a professional.

If you do have a pressure gauge and would like to attempt measuring the pressure levels yourself, make sure you are taking the necessary precautions since refrigerant can be a dangerous chemical. Check your manufacturer’s specs to find out what the ideal pressure levels are.

Your energy bill is higher

A higher-than-usual energy bill is one of the tell-tale signs of an overcharged AC. The downside to that is you probably won’t realize it until the problem has been going on for a month or so. Hopefully, it hasn’t caused any other problems with your AC by that time.

The reason this happens is if you have too much coolant circulating through your air conditioner, it will cause more stress on your air conditioner and cause the compressor to work harder, which will increase the amount of energy used.

Your AC shuts down completely

I’ve often found that if your AC shuts down completely and you can’t find anything else wrong with it, the excess refrigerant may be to blame. Most ACs are designed to shut down when they are being overworked past a certain threshold. When the system can’t handle that amount of stress, it shuts itself down to prevent further damage.

If you have an overcharged system and you don’t take care of the problem in a timely manner, it will spiral into even bigger problems for your air conditioning unit and could result in total system failure.

2 Things That Can Happen If You Overcharge Your AC

So what will actually happen if you overcharge your AC? Well, overcharging your air conditioner can cause serious problems. If you do it too often, you might even destroy your air conditioner completely.

The two things that are most likely to happen are, it will blow out hot air, and it will also likely cause damage to the compressor, leading to further issues down the road. 

Let’s take a look at those two common instances in more detail.

Damaged compressor

As I mentioned before, if you don’t catch the problem in time, and you keep running your overcharged air conditioner, it could lead to a damaged compressor.

That can happen because extra refrigerant can accumulate inside the compressor and cause temperatures to drop to a lower level than normal. Then the additional refrigerant can cause the compressor to flood and damage its mechanical components.

If the compressor fails, your AC will no longer cool the room because the compressor is what pushes cold air throughout the entire system. When it breaks, there’s no way to push cold air around the home.

And when the compressor stops running, the fan won’t work either. Without the fan, the temperature inside the house rises quickly.

It’s usually not cheap to fix a compressor, and it might even require replacing the whole air conditioning unit. So if your compressor has been damaged, I would recommend consulting with an HVAC expert to see if it is fixable. 

To prevent compressor problems, the most important thing to remember is that you shouldn’t overcharge your air conditioner. You should always follow the manufacturer’s recommendations when charging your unit or have a professional do it for you.

Your AC blows hot air

The more refrigerant you have in your system, the harder the compressor has to work to move that refrigerant around as part of the cooling process. If the compressor has to work too hard, it will cause excessive hot air to come out of your AC unit. 

This could also be a result of the extra added pressure that is in the coil from overfilling it. 

What to Do If You’ve Overcharged Your AC?

If you suspect that your air conditioner is overcharged or your AC is running constantly, I would recommend calling a professional asap. Don’t attempt to repair it yourself, and don’t wait too long because you don’t want it to cause permanent damage to your air conditioner.

Refrigerant is a dangerous substance that can cause pollution if it leaks into the environment so it has to be disposed of carefully. In fact, most cities have laws about the proper disposal of refrigerant and you don’t want to get fined for doing it wrong.

So the best course of action is to call a professional who knows how to properly charge your air conditioner. They will know exactly how much refrigerant is needed and how to safely add it.


So if you’re in the middle of one of those hot summer months and you happen to notice that your AC is just not cooling like it used to, think if you have recently had any maintenance done on your AC or if you have tried to add some refrigerant yourself.

Go through my list of signs, and if something seems off, chances are you went too far and overcharged the system. Call your local HVAC professional immediately so you can get the refrigerant levels leveled out and get back to enjoying a cool house.