Your Loud, Annoying, Noisy Air Conditioner
It’s summer. It’s hot. Air conditioning is great. Unless…you can’t even get a good night’s sleep thanks to your noisy air conditioner.
You can’t go without A/C, so what do you do? Is that noise even normal? Should you call someone?
Don’t worry. MrCool is here to help.
Diagnosing a Noisy Air Conditioner
There is one big question you should ask about a noisy air conditioner: “Is the noise normal or the sign of a problem?”
Depending on your air conditioner’s age, the noise might be normal. Older units lack the insulation and noise-reducing technology many new units have as standard features. What you want to do is listen for a few key indicators:
- Grinding: Grinding is bad. If you hear it, it’s probably coming from the fan motor. The bearings in the motor can wear out after a long operating life. When they do, they start grinding. You’ll need to get the fan motor replaced, since total fan failure is probably not too far off.
- Rattling: A rattling noise can be a big deal or a little one. Sometimes leaves and twigs can get caught in the vents, and sound really bad when you hear them. They’re not a big deal. Clean them out and you’re good. Rattling inside the compressor itself is a problem. It means operating wear and tear is starting to build up, and your compressor may be on its last legs.
- Hissing: If you hear a sharp hissing noise coming from the unit itself, that means one thing: refrigerant leak. Modern refrigerants are rarely dangerous to humans, but replacing it is expensive. Contact an HVAC professional immediately when you hear that noise.
Those are the major problem sounds you need to listen for when it comes to worrying about a noisy air conditioner.
And, remember, if the unit’s just loud, it’s probably just old. The only way to permanently solve that is with a new air conditioner that, purely by coincidence, we would be happy to sell you.
26 thoughts on “Your Loud, Annoying, Noisy Air Conditioner”
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MR COOL
Master of All HVAC
How loud is the outdoor unit? We will have on the exterior bedroom wall. Will this be noisy if it’s mounted there? And is vibration associated with it being mounted on the wall?
The outside condenser is not very loud especially compared to a traditional air conditioner condenser. It has rubber pads you can use during installation to mitigate any potential vibration.
Do you have a decibel rating for outdoor units?
Yes. Depending on what unit you’re interested in, they are located on either the brochure or the spec sheet for the particular system. You can find them on the Documentation page at https://mrcool.com/documentation/.
My inside unit is humming, a low grade constant low humming, that sounds like white noise, but t is so annoying.
My unit is making a high pitch whining noise on start up after a minute or two it goes away, any suggestions?
Please call tech support at 270-366-0457.
18k single zone unit about 2 years in service. Makes a click, click sound about three consecutive times when the unit is turned on and the louver is moving to its open position. Also make the same sound periodically while on. No noise when louvere is closing. Any ideas?
My inside unit makes a whirring sound during operation. Is that normal?
You may want to check if your louvers are aligned appropriately. Softer noises may be common during operation, but if it sounds loud, obtrusive, or as if things are grinding together, please give us a call at 270-336-0457 as quickly as possible.
I have 3 units in 3 different bedrooms within my house. From an AC perspective i assume they run from the one unit that sits outside. All of the units (3 inside and 1 outside) are less than a year old. So far this year i have turned the AC on 2 times. the first time we thought someone was breaking into the house in the middle of the night. It sounded like some kind of wild animal was growling in the living room. The second time i turned on the AC the same thing happened in bedroom 1. I turned off unit and it stopped. an hour later it happened in the living room. same, i turned off and it stopped. 2 hours after it happened in bedroom 2. The sound is a loud grinding and sounds like its breaking. Any advice?
Please give us a call at 270-366-0457 as soon as you possibly can.
I just installed a Gen 3 system and there is a thumping sound from the indoor unit. Is this normal?
Please give us a call at 270-366-0457 as soon as you possibly can.
i have three air handlers an 18k and two 9k the 9k units during operation sound like water boiling is that normal
Please give us a call at 270-366-0457 as soon as you possibly can.
My newly installed MC 5 ton inverter runs very quiet in heat mode until what seems to be the compressor kicking on. Then I hear a noticeable vibration noise (enough to wonder what the neihbors think). 45 deg outside today so not related to ice. i then put wood blocks under the unit / slab to absorb the vibration and that helps quite a bit. is this compressor noise common? is it possible i lost a little r410a causing the noise? I have a 50ft line set.
You may want to have an HVAC professional make sure that the unit is set correctly. Otherwise, please give us a call at 270-366-0457. It should not have lost any refrigerant, unless the vibration was extreme.
My new 5ton inverter lasted 1 day and then gave me H4 overload error. What’s next?
Please give us a call at 270-366-0457 as soon as you possibly can.
My mr cool I door fan surges. It is about 2 years old but has only been installed for about 2 months. It has done this since it was first installed 2 months ago.
We apologize for this. Please give us a call at 270-366-0457 as soon as you possibly can so that someone from our tech support team can assist you with this.
Loud vibrations and grinding from the unit from the time of purchase. Had it for about a year now and it comes and goes. Also receive a P0 and P4 error code as well. I believe I still have warranty on this unit please help.
Please give us a call at 270-366-0457 or send us an email on our contact page at https://mrcool.com/contact/
I have a 18k Mr cool single unit. The AC is now making a high-pitch noise whenever the fan is running, doesn’t matter the mode. The higher the fan speed the louder the noise. Happens even when only the fan is running. Not sure what the issue is but it’s annoying. The unit heats and cools without issue. Is it possible to only change the indoor unit? The outdoor unit works fine
Please give us a call at 270-366-0457 as soon as you possibly can so that someone from our tech support team can assist you with this issue.