Why Is My Air Conditioner Making Noise Even When Its Off?

Most people expect their air conditioners to make a bit of noise when it’s on. But if a buzzing kind of sound persists even after your air conditioning shuts off, it could be because something isn’t working properly. Whether it’s a faulty motor or an erratic electrical connection, it’s worth checking out. Otherwise, your air conditioner could stop working altogether. 

Contacting a professional technician is the best idea when your air conditioner is making noise, since they can quickly find the source and begin repairs. In the meantime, here’s some useful info about why your air conditioner could be noisy. 

First, Find Where the Sound is Coming From 

Tracing the sound back to its source can help the technician narrow down the possible causes. Your central air conditioning system is made up of two units. The outdoor unit disperses the heat collected from your home and cools it down with the refrigerant. This cooler air is sent to the indoor air handler, which ensures the conditioned air is sent into the ductwork. If the noise you’re hearing isn’t coming from either of these units, the problem could be found inside the ductwork itself. 

If the sound is coming from the indoor unit: When noises are coming from the indoor unit, it can often be because there’s something wrong with the blower motor. A faulty electrical connection could cause the motor to make a buzzing sound regardless of if the air conditioner is on. 

Sometimes, however, the noise comes from your condensate pump. This component helps drain excess moisture away from the rest of the AC system. It may continue to run after a cooling cycle is finished if there’s still moisture that needs to be removed. 

If the sound is coming from the outdoor unit: Just like the indoor unit, the outdoor unit uses a fan and motor. But instead of sending cool air into your ductwork, this fan is used to dissipate the heat collected from indoors. A bad connection could produce a similar buzzing sound, and since it’s outdoors, it could be a while before you notice it. 

The outdoor unit also houses the relay switch, an important component for stabilizing the voltage that enters the system. When this part makes a sound, it might have failed and will need to be replaced. 

There’s always a chance that a screw has shaken loose or a piece of debris has gotten trapped somewhere inside the system. This can happen to both the indoor and outdoor unit, and will produce a variety of noises depending on where the object is lodged. If this is the source of the annoying sound, you shouldn’t hear it for very long after the AC shuts off. To make noise in the first place, it’d need to be close enough to something that could cause it to rattle against the unit housing. 

These Noises Are Most Often Because of an Electrical Problem 

You may have noticed that a lot of the possible causes of this unusual noise have something to do with electrical components or the connections themselves. Since most components won’t work without power, a malfunctioning electrical part is the most common reason you’ll hear something even when the air conditioner is off. After your technician has found where the sound is coming from, they’ll probably start checking components like the relay switch and compressor, as well as all connections. 

Even if you’ve located the source of your problem and think it’s an easy fix, it’s best to let a licensed and insured professional resolve electrical problems. 

Leave Electrical Problems for the Pros 

If your air conditioner’s electrical system is malfunctioning or damaged, calling a professional is the right move. There are several reasons why: 

  • Electrical problems can be hazardous: Service technicians have the training, licenses and insurance for safe and effective resolutions to electrical malfunctions. 
  • Improper repairs can end up doing more damage: Even if you think your DIY skills resolved the problem, it may have ended up doing more harm than good. Air conditioning systems are still complex machinery, after all. 
  • Pros can spot other problems: Technicians with years of experience are more likely to notice when something else is plaguing your HVAC system. They can handle it right there instead of letting the issue spread or worsen. 

Other Common AC Noises 

Getting familiar with several other noises that may come from your air conditioner is a good idea. The next time something is wrong, you may be able to recognize it right away and call for professional service. A few other unusual noises include: 

  1. Trickling or Hissing: A leak is the most common culprit. Air leaks are inefficient but can be simpler to resolve. If the coolant is leaking, however, that might spell big trouble. Components related to the refrigerant supply are costly to fix and may end up resulting in having to replace the entire air conditioner. 
  1. Clicking or Ticking: When running normally, you’ll hear clicks as electrical components start up and direct the air conditioning to run. When there’s an electrical problem, these clicking sounds can happen at random. 
  1. Clanging or Rattling: These sounds are often because of a loose screw or a piece of debris. But sometimes it’s a piece of a more important component such as the compressor. The compressor is airtight, so if something breaks off inside it, you might be stuck with an unpleasant rattle until it’s fixed. 

Call Service Experts Heating, Air Conditioning & Plumbing for Quiet, Comfortable Cooling 

If something doesn’t sound right, don’t wait and see if it goes away by itself. The faster a professional technician can start repairs, the quicker things can be resolved. You’ll enjoy a quieter air conditioner and efficient cooling. 

Request an appointment with the HVAC pros at Service Experts Heating, Air Conditioning & Plumbing today by giving us a call at 866-397-3787. 

  • Zoning Systems: Customized Comfort in Every Room

    Central heating and cooling systems have revolutionized home comfort and made it possible to stay completely comfortable in any season or climate. However, while centralized systems are a handy way to manage the temperature, they occasionally fall short when it comes to evenly distributing heated... Continue reading

  • Eight Ways to Upgrade Your HVAC System

    During the cold winter months in the U.S., there’s no better way to improve your home’s comfort than with a few effective upgrades. It’s not only about keeping the house toasty warm as the snow begins to fall—it’s about enhancing efficiency and removing pollutants from the very air you... Continue reading

  • How to Find a Suitable HVAC System

    When considering keeping your home comfortable all year, nothing is more essential than picking out the right heating, ventilation and air conditioning (HVAC) system. This decision influences your daily comfort, monthly utility costs and all-around home efficiency. But, with so many system types,... Continue reading