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Max Sr & Paul Schoenwalder Plumbing, Heating and Air Conditioning, A Corp. Blog

Several Sounds You Should Hear Your Air Conditioner Make

woman-holding-hand-to-ear-to-listenIf you’ve ever read an AC repair blog that tells you some of the signs that a system is in disrepair, then you know that strange noises are one of those indicators. We often spend time telling customers what their air conditioner shouldn’t be doing, and as such, it can be easy to forget to explain what an air conditioner should be doing.

After all, air conditioners are big, complex, pieces of machinery and they are always going to make some noises that might be questionable. But the fact of the matter is, not all noises need to cause alarm. Read on as we put these sounds in context.


This is actually a vital noise your air conditioner will make–the humming of the compressor. The compressor is considered the “heart” of your air conditioner and when this component comes on, it begins your AC system’s cooling cycle.

It means that your air conditioner received a signal for the thermostat that your household requires cooling, and the compressor’s motor starts up so that its liquid refrigerant can be pressurized and changed into hot gas in order to carry out the heat exchange process.

Along with this humming should be cool air coming through your vents. If you aren’t getting that cooled air, it means either your system is on “fan mode” and you’re actually hearing the fan running, or there is something amiss with your cooling system.

Fan Running

The indoor unit of your air conditioner houses the blower fan, which pushes air through the air conditioner and then into the ductwork. The noise of the fan should be gentle and steady–during the summer season, it’s an almost constant white noise.

Water Moving

This is another sound you’ll hear from the inside unit of your air conditioner. It’s not a noise you should hear constantly, but rather at periodic intervals. If you’ve ever noticed a window air conditioner at work from the outside, you’ll see water condensation forming and dripping from it.

This is the same condensation that you’ll hear inside your centralized AC system, but instead of dripping freely, it exits to the outside through a drain line and drain pan.

Ductwork Rattling

If you hear intense rattling that you’ve never detected before coming from your air conditioner, then it’s time to call us for potential repairs. If, however, you detect a gentle rattle when your air conditioner (or heater) cycles on and off, this is normal.

What’s happening is that the temperature is fluctuating inside the ductwork, and the ductwork itself is slightly expanding or contracting due to that.


Yes, some clicking is actually normal when it comes to your cooling system. When it finishes a cycle, the machinery needs a bit of time to completely stop, and as a result, you’ll hear the compressor and motors shutting down.

If, however, you hear clicking at other times, or the clicking is getting louder–especially if we’re talking about a gas-powered heating system rather than an air conditioner–it’s time to give us a call!

Established in 1912, Max Sr & Paul Schoenwalder Plumbing, Heating and Air Conditioning, A Corp. is your trusted resource for reliable AC repair and much more. Reach out to us today.

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