When you have a central air conditioning unit, you are most likely used to the normal humming or occasional clicking noises it makes while it is running. However, if you hear either of the noises discussed below, your A/C unit may have a major problem that requires the immediate attention of a professional.
1. Hissing Sounds Heard after the Compressor Shuts Off
One sound for which you should keep your ear open for is a hissing noise that is most often heard after the compressor shuts off. While this hissing may occur while the A/C unit is running, the sound may be low enough that you do not hear it over the motor and compressor.
If you do hear a hissing sound, the most likely culprit is air bubbles in the refrigerant line. Since the line is part of a closed system, the only way that air can get inside of it is when there is a refrigerant leak.
Not only will the refrigerant level decrease rapidly if left unrepaired, but once the line runs dry, the lack of refrigerant can damage the compressor. As soon as you hear the hissing noises, you will need a professional to find and repair the leak as well as to refill the refrigerant.
2. Grinding Noises While the Unit Is Running
Another sound that is cause for alarm regarding your air conditioning unit is a grinding noise. One of the major problems this sound indicates is a problem with the air handler, which is responsible for pushing air through the system and throughout your house.
For the air handler to work properly, the bearings must be kept well lubricated. If the metal bearings become dry, they will rub against and wear each other down.
Eventually, the friction will wear the bearings down to the point that they are no longer able to move the handler smoothly, possibly causing it to break down completely. A repair technician will be required to relubricate or replace the bearings to keep this from happening.
If you hear either of the above sounds coming from your home's central air conditioning unit, there is a strong possibility that it could break down completely if you do not have the problem fixed promptly. Contact an air conditioning service so that a professional can inspect the unit and repair whatever is causing the problem as soon as possible to prevent further damage and issues.