(314) 402-8240
Expert HVAC Service

Why Is My Air Conditioner So Loud?

You may wonder sometimes why your air conditioner is so loud. Well, it makes a normal humming noise all the time. You get home from work and you can hear it being loud, this could be the first sign to something of trouble. We are going to go over some of the common noises that you should be hearing and the ones that should concern you.

Toddler with Hands Over Ears Because It Is Loud Outside

Noises a Central Air Conditioner Can Make

Review this check list of common noises you might experience with your central air conditioning system.


I heard a loud noise in my air conditioner. Why is my AC making a popping noise? Well actually, this is a very common misconception. What you heard is the ductwork. When the air kicks on it, all expand and sometime you will hear that expansion in the form of a popping sound. If you constantly hear, this noise while the unit is running you would want to call us. It should not pop but once when you kick it on.


Why is my air conditioner making a grinding noise? The most common noise that you will hear grind is the fan motor. These motors have bearings inside them. Like with all things, these bearings can be worn down and create a nasty grinding noise. Shut the unit off and call a certified HVAC technician.


Why is my air conditioner hissing? Two things can cause this. The first would be a refrigerant leak. When you can hear a hissing sound, I would recommend calling an HVAC expert immediately. The ductwork can make a whistling or hissing noise as well.


Why is my air conditioner making a rattling noise? If you have, children always check your vent and make sure there is nothing in there. We see this all the time. The sound could also be coming from inside the compressor. The motors start to age and the sound can get louder. This does not always mean there is a problem with it. The yearly maintenance that your HVAC company provides will usually clear this up so you do not need to worry.


My air conditioner is making a banging noise. This is usually the sign of some loose parts inside the unit. You should shut down the unit and check around the AC to see if you can find anything that might be lost.


My air conditioner is making a clicking noise. When the AC tries to turn on and you are hearing a clicking, this usually means something to do that is electrical. This can be everything from the thermostat to the electrical board. You have to remember even though you see big things of metal. Your system is made up of all kinds of electrical pieces.


My air conditioner is humming. This could be signs of a burnt fan motor. You will want to make sure you turn it off immediately!

Diagnose Central Air Conditioning Noises

In this more technical video, Craig Migliaccio goes over some of the sources of noise from an outdoor air conditioning unit:

How Do I Prevent My Air Conditioner from Making Noises?

The first thing that we recommend is to call your local HVAC Company and set up your yearly maintenance schedule. This way you never have to worry about any of this. You are too busy and should not have too. You can give your air conditioner a go over with a screwdriver and just make sure that everything is tight and secure as well. Sometimes you might find a loose bolt that causes a rattling sound.

To reduce noise from an air conditioner some people build fences around them to cut them off from the outside. The problem is access to the unit. Then weeds and shrubs start growing around the fence and start getting into the unit. They have some soundproofing solutions as well. This can start to get pricey, though. We have seen sound blankets but have heard these can reduce efficiency in your system and that will cause a whole new set of issues.

Remember a little noise is okay. It is supposed to because if it is silent it is either off or useless. You should also check your ac filter to make sure it is nice and clean. Each filter has a regulation on when it should be changed. We usually tell people depending on how much you are running it at least change it every month. The filters can become clogged with pet hair dust and debris. A home warranty or protection plan from an HVAC contractor will help you stay protected all year long.

Why Is My AC Making a Loud Noise?

Today’s air conditioners are high-efficiency and have sound dampening technology pre-installed to help keep the noise down. When you hear a noise and you ignore it, it could cost you thousands. The faster you can determine the noise and get it fixed the better.

Of course, some of the older units are a bit louder. Over the years, units have more efficient causing them to quiet down quite a bit. So if that outside unit sounds quite loud this is nothing alarming. If that air conditioner is keeping you up at night and you feel that, it is a bit too loud. You can contact your St Charles HVAC company and talk to them about devices that can help quiet the unit. You should always set up a yearly inspection for your unit. This will always help keep it running in top condition. They do a full test run with the air conditioner so they will look for dirty fan blades or parts that need lubrication.

We do have noises that require a bit more attention. If you hear a bolt in there, sounding like it is being grinned to pieces or something rattling shut it down. Call your HVAC company immediately. Remember the time you decided not to change the brake pads on your truck and it started grinding bad? Well, if your air conditioner sounds like this, call your HVAC company: No Problem Heating and Cooling.

Schedule Service or Request a Quote

Areas We Serve

Proudly installing, repairing, and maintaining all types of residential and commercial HVAC systems in St Charles and the St Louis Metro Areas.

  • St Charles County, Missouri
  • St Louis County, Missouri
  • Warren County, Missouri
  • Franklin County, Missouri

How Can We Help You Today?