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Weird HVAC Noises and When to Worry

HVAC troubleshooting Austin

It’s happened to all of us: you’re sitting in your living room, enjoying a good book or TV show, only to hear the strangest sound in the other room. As you peer down the hall (perhaps with a baseball bat in hand) you finally find the source: your heating and cooling system. After a sigh of relief, you might grow concerned. What does that weird HVAC noise mean? 

Mostly, curious sounds from your heater or air conditioner are a sign that your unit needs repair. HVAC equipment should operate quietly. Since minor issues often develop into major problems (or even breakdowns) it’s a good idea to call an HVAC professional for repair ASAP. Below, we’ve detailed out some of the more common heating and cooling noises you may hear and what each of them could mean. 

Banging, Thumping, or Rattling Sound from AC Units

This is one of the most common sounds our customers report and unfortunately, there’s no single answer to what it means. When you call for repair, it’s helpful to indicate whether the sound happens all the time during operation or if it is intermittent.

If you’re hearing this odd noise above your ceiling, one likely culprit may not be your equipment at all. It could be your ductwork! If the ducts were not properly installed, a section has come loose, or if certain duct runs are closed off, it can create these sounds. 

If you’re sure that rattling or banging sound is coming from a piece of equipment, it could be a sign of a loose component in the unit. This is a fairly simple fix, although reconnecting any loose parts will require the help of a NATE-certified technician

Screaming or Squealing Sounds

When HVAC units are making high-pitched sounds, we’d bet they are pretty old units. Older systems use a belt-driven motor and you’ll hear that squealing noise when they come loose. We can replace the belt, but this might be a good time to consider if it’s really worthwhile the tradeoffs of repair vs. replacement

If it’s not the belt, or if you have a newer unit, there are a couple of other areas we would inspect. The bearings on your fan motor could need replacing, or potentially it’s an issue with your compressor. Regardless, this type of noise is NOT normal and will only get worse with time, so call us today to get it repaired.

Buzzing, Vibrating, and Rumbling Noises

An electrical problem usually causes a popping, vibrating, or buzzing noise. There are many potential source points for an electrical problem: wiring, motors, or even the connection to the circuit breaker. Of all the noises to have, this one is very important to address quickly. Call in a trusted professional like McCullough to investigate. 

Tell us About Your Weird HVAC Noises!

Tracking down and fixing HVAC problems is kind of our thing here at McCullough. Call us and describe the sound you’re hearing: hissing, bubbling, screeching, squealing, buzzing, clicking, banging, or vibrating. You can even take a short video on your smartphone and text it to us! This way, we can have a better understanding of the problems you’re facing, so we can be prepared to address it quickly. 

We’ll send a technician experienced in this type of repair, along with all the tools and parts needed to fix it. Remember: these weird sounds will only get weirder (and louder!) so address the problem as soon as you’re able. Contact us 24/7 at (512) 866-9821 !

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