The room should light up when the switch is turned on, but there should be no accompanying buzzing noise. A buzzing light bulb is not just an annoyance but also a possible sign of an electrical issue. Fixing this hum is usually straightforward as long as you know what to look for. It's not always the light bulb causing the vibration; sometimes, the other appliances share the same power supply.
Why Do Lights Buzz? Common Root Causes
The voltage delivered to the bulb, rather than the bulb itself, is usually to blame for lights that buzz. This problem may arise from anything using the same power supply.
Incandescent Bulbs
The most common type of dimmer switch uses a triode for AC (TRIAC) dimming. The buzzing or humming sound is caused by the filament vibrating due to the constant application and removal of voltage, which excites and cools the filament. Switching to a rough service bulb can reduce the vibration and hum. The thicker filament in a 130-volt bulb also helps to dampen annoying buzzing. Vibration can also be minimized or eliminated by switching to new dimmer switches. To save money, switch to lower-wattage bulbs or acquire a newer dimmer with a higher wattage rating.
Fluorescent Lights
Fading and buzzing are common problems with older fluorescent lighting. Even if the bulb is burned out, replacing the bulb won't help if you have an old ballast. The voltage of fluorescent lights can be controlled by this device. The buzzing could be due to the ballast's inability to regulate the voltage.
LED Light Bulbs
The incompatibility between the LED light and the dimmer switch is usually the cause of humming or buzzing in LED light fixtures. Not only is this a safe way to determine if the switch is to blame, but it can also be a helpful way to do so. If the dimmer is not in use, you can disconnect its wiring and connect it to a standard light switch. Alternatively, you could disconnect and join the two live wires using a wire nut.
A few additional lighting components may be the source of the buzzing or humming. Similar 'on/off striking may be caused by electrical shorts or carbon buildup on electrical connections. An electrician should inspect and fix the problem if a short is suspected. A similar but more metallic-sounding buzzing might come from a source such as loose fittings, where a screw can produce vibration in the fixture. Repairs might vary from changing a single bulb to installing a new circuit board.
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