Is Your Home Air Conditioner Making an Unusual Humming Noise?

Getting the maximum benefit from your home comfort system in summer means saving a few hundred dollars on your monthly bill. This is highly probable if you are practicing the best tips to optimize the efficiency of your cooling system.

In some cases, however, some factors highly affect the performance of an air conditioner. A dirty filter can lead to clogging which blocks the ideal airflow. Clogging can lead to fan blower failure and cause overheating and a possible fire hazard. And some point, the age of the unit also holds immense weight on the AC’s overall functionality.

Multiple reasons can cause different issues, but let’s focus on one particular concern that many people can easily detect as a possible problem – a constant humming noise when the system is running.

Strange Humming Noises

AC serviceThe humming noise coming from the cooling unit can be because of one problem or a combination of several others. Whatever it may be, if the noise is constant and continuous, call an HVAC professional. This is a job trained technicians can easily handle. It can vary from a simple tune-up job, a part replacement, or something else entirely. Even so, learning what the possible causes might be can help you determine the type of job that your AC may need.

Loose Parts. A humming noise usually occurs when the hardware within the unit is loose. In addition to the consistent hum, small metallic dings can be heard so often as well, an indication that the nut is tapping against the bolt. This can be fixed by opening up the unit to tighten the nut. For safety purposes, the unit must be turned off before this is performed.

Seized Compressor. A soft hum can be heard when the unit is on, but when it does not release cooled air while running, the problem might be seized compressor. The compressor is responsible for pumping and pressurizing the refrigerant to move through the system. As it works, it runs hot (up to several hundred degrees). This device relies on a few ounces of oil (as a lubricant) to work smoothly. When oil leaks or breaks down due to contamination, the compressor will fail. This failure will result in an unpleasant humming noise. Cleaning it might be a temporary solution, but a part replacement is ideal when the damage is severe.

There’s more information about compressor defect in this article.

Other Unpleasing AC Noises to Watch Out For

Aside from the irksome humming, there are other noises that the AC produces that also indicate performance issues. Here’s a list from

  1. Banging – Banging is usually a sure sign that there’s a loose or broken part — a connecting rod, piston pin or crankshaft — inside the compressor.
  2. Clanking – Clanking is another sign of a loose or out-of-balance part. The parts inside the sealed unit have likely failed, and the compressor itself may have become loose, possibly necessitating a replacement.
  3. Clicking – The clicking of electrical components at start-up and shutdown is a normal part of the system’s operation, but constant or ongoing clicking is not typical. It could be a sign of a defective control or a failing thermostat.
  4. Screaming – If you hear high-pitched whistling or screaming, shut the air conditioner off and call a professional right away. The most likely cause is a refrigerant leak, which not only damages your unit but can also threaten your family’s health. Screaming might also indicate high internal pressure within your compressor, which is very dangerous.

Air Conditioning Service, Maintenance, and Repair

Marthedal Solar, Air & Heating services, maintenance, and repair is always customer focused. We ensure that clients get the most out of their AC service. Our home automation technology allows homeowners to take control of their systems on the go.  Read about setting your thermostat or improving your air filter.

Is Your Home Air Conditioning Service Making an Unusual Humming Noise?