Mostly any noise you hear from an electrical outlet will be a buzzing sound. These noises are not normal. Nor should they be ignored because the sound can be the beginning of a serious problem.
Here are the main causes of outlet noise and some of the ways to fix it.
4 Causes of Outlet Noise
Buzzing electrical outlets are an indication of some kind of malfunction in the system. The problem should be looked at sooner rather than later because it could possibly lead to bigger problems like electrical fire, shocks, or more serious electrical issues.
1) Loose Electrical Connections in the Box
It doesn’t seem to make much sense, but electrical wires come loose. (How can that happen? They are in a box that does not move.) Whether it is a wire attached to the receptacle, or the wires connected by a marrette (twist-on wire connector), when they come loose, they will vibrate causing the buzzing noise you hear.
Loose connections can actually cause the entire receptacle to vibrate, making a louder noise. Older homes with older wiring are more likely to have buzzing outlets caused by loose wires. If only because they are older.
Turn of the appropriate breaker. Then to fix this problem, remove the cover and receptacle. Check all marretted wires, screws, and push plug fittings to be secure and tight. Replace everything in the box and turn the power back on. Hopefully, you have solved your problem.
Note: Loose or bad wiring can also cause arcing and wear and tear on the circuit breaker.
2) Broken Breakers
As mentioned earlier, breakers can be weakened by loose wires. Your breaker also may be providing too many or too few amps to the outlet. This will likely be causing the buzzing sound you can hear coming from the outlet. If this is the case, you may have to change the breaker if tightening the wires did not solve the problem.
Changing a breaker is usually quite simple. Turn the main power off before removing the cover. Sticking your hand into the box with the power on is a very good way to stop your heart. Breakers produced by different manufacturers are generally not interchangeable. Only buy breakers that match.
3) Worn Outlet or Receptacle
Contact blades inside the receptacle are made to hold the plug blades snuggly and make positive contact to provide a steady source of power to whatever is plugged into the outlet. These internal blades can become loose or worn making for bad contact which will cause the buzzing noise. A good indicator of outlets wearing out is loose appliance plugs.
To replace a receptacle, switch off the breaker that powers it, remove the cover, pull out the receptacle, and disconnect the wires from it. Attach all the wiring to the new receptacle, screw it back onto the box, replace the cover, and turn the breaker back on. Your buzzing should be gone.
4) GFCI Outlet Problems
More and more building codes specify GFCI plugs–especially in bathrooms, kitchens, and outside. They provide more safety than traditional receptacles because of the built-in breaker. But some of them come with a bit of a built-in problem. They hum or buzz when being reset. Sometimes this can last for a few seconds after you push the reset button. If it lasts longer, try pressing “Test” and then resetting it again. If the noise persists, it is probably time to change a receptacle.
Other than that peculiarity, GFCI receptacles can have all of the same problems as regular receptacles. And you can use the same DIY fixes on them.
Some Additional Causes of Buzzing Outlets
Here are some of the other possible causes of the noise you are hearing.
- Faulty Appliance or Lamp. Sometimes the buzzing will be coming from the lamp or appliance you are plugging in–not the outlet. Because they are close together, you can make a false diagnosis. Try another appliance to check.
- Dimmer Switches. Dimmer switches will often cause humming in both the light fixture it is connected to and sometimes in other receptacles on the same circuit. If you cannot stop the noise by changing bulbs, you may have to consider replacing the dimmer with a regular switch.
- Certain Devices. Some things may cause buzzing when plugged into the same circuit. Unplug everything to see if the noise persists. If the noise goes away, your problem is something you are plugging into the circuit. (For instance, charging my electric drill on the same circuit as the garage radio amplifies the humming through the speakers. Very rude.)
- Temperature Changes. Temperature changes will cause electrical equipment to expand and contract. This can loosen connections and even marrettes because different materials expand and contract at different rates. Although this might be a recurring problem, it is easy to fix. Make sure all the connections in the box are tight. (Turn off the power when working on it.)
- Faulty Wiring. The wiring in your home may not have started out faulty, but over time it could have become corroded or rusted. This will cause humming in the outlet and potentially cause problems for the entire circuit including the breaker. If you find rust or corrosion in the electrical box, you will have to clean off the ends of wires, cut off the faulty parts, or replace them. Quite likely you will also have to replace the receptacle.
Call an Electrician
If you have a nodding acquaintance with electrical wiring, you will find most of these repairs to be fairly simple and quick. On the other hand, if your understanding of electricity matches your understanding of quantum physics, call an electrician to take care of the problems. Give some consideration to having a quick inspection of your electrical system while he/she is there. A little preventative maintenance might be a good thing.