No air conditioner is completely silent, but there are certain sounds that you should never hear when running your AC. If your air conditioner is making strange noises, the good news is that the type of noise you hear can help to point you to the problem. Here are three possible causes of a noisy air conditioner.
1. Loose Cabinet Access Panel
It may sound surprising, but you might be able to solve your noisy air conditioner problem without looking inside your air conditioner at all. If your air conditioner is making a rattling noise while it's running, you could be hearing the cabinet access panel vibrate against the furnace housing.
Even when you are only running your air conditioner, the blower can vibrate enough to cause the furnace access panel to rattle. A good way to test if the rattling is due to a loose access panel is to simply hold your hand against the panel after you turn your air conditioner on. If the noise goes away, try tightening the screws holding the panel in place.
2. Blower Motor Needs Lubrication
A grinding noise inside your blower assembly can be an alarming sound, but there may be a quick fix. The grinding could be the sound of the bearings in the blower motor rubbing against each other. Lubricating the blower motor is often all that's needed to get it running smoothly again.
Many central air conditioner blower assemblies have oil ports that homeowners can use to add oil to their system. Remove the access panel and look for these ports above the bearings near the motor shaft. Add a few drops of 10-weight motor oil to each port once a year to keep the blower lubricated year-round.
3. Refrigerant Leak
When your air conditioner is leaking refrigerant, it may start freezing up and often won't deliver the cooling that your home needs. However, a noise could alert you to a smaller refrigerant leak before these problems develop.
If you hear a hissing noise inside the blower assembly or outside near the condenser, your system may be leaking refrigerant. Refrigerant is pressurized inside your system's coils and coolant lines, and will escape like any pressurized gas if there is a puncture. Contact an HVAC technician to inspect the refrigerant level and recharge your system if necessary.
Odd noises from your central air conditioner aren't always a sign of a serious problem. Keep these tips in mind so you can hunt down the source the next time your air conditioner is making noise. For more tips on recognizing and dealing with broken air conditioners, talk to an air conditioning service in your area.