Here’s a fun fact: Almost all dimmers hum. When the room is absolutely silent, and the bulbs have been dimmed down to less than 50%, you put your ears close to the dimmer switch.
Chances are, you will hear some buzzing or, at the very least, humming.
But the problem arises when the buzzing is very audible and stressing you out. And more than that, you are worried if this buzzing will cause a short circuit, an electric shock, or even a fire!
Dimmer switches do make a slight buzzing sound due to the interruptions to the electromagnetic field that naturally exists around a live wire. A buzzing sound from the switch is usually not dangerous, unless accompanied by a hot switch or a crackling noise.
Why Does Dimmer Switch Buzz When Light Is On?
So you’ve got up one fine day and turned on your dimmer switch, but it is causing a loud, unignorable buzzing sound. I am here to help!
Firstly, get the basics out of the way.
Make sure all the wires are screwed in tightly and are securely making contact. Make sure you shut off the power when you remove the face cover to tighten the screws.
Of course, the second necessary fix is to make sure that your dimmer is not very old. Normal wear and tear of the wiring and switch can cause buzzing to occur. Ten years is the paper limit for a dimmer switch if it has not been overloaded.
For a little bit of context, you should know that a wall switch can only handle wattage’s extent connected to it. For a 10-15 amperes circuitry, you can usually install 1800 watts. But dimmer switches can handle the lesser load.
So when you load many bulbs of a high wattage onto a single dimmer switch, buzzing can start. Swap out high wattage bulbs for lesser ones, and that may fix your problem.
The next reason could be an incompatibility. Older dimmers work well with incandescents that need 240 Volt AC current.
But newer LED technology lighting works on direct current.
When used with a traditional bulb, the dimmer evenly alters the voltage going into the circuit and bulbs to dim it. An LED bulb cannot respond to that gradual change in voltage, and either the bulb or the dimmer may start to buzz.
This mismatch when new LEDs are plugged into old dimmers, results in a variety of issues, including buzzing from the dimmer switch.
Keep in mind that you may think the buzzing is coming from the switch at times, but it could be the bulb.
A standard dimmer switch wired to an incompatible LED fixture or the bulb will produce a humming sound as it turns on/off at irregular intervals, indicating electromagnetic interference (EMI).
The most problematic bulbs with dimmers seem to be the CFLs, the compact fluorescent bulbs. The circuitry of CFLs can be quite incompatible with dimmers and cause a buzzing sound.
Get bulbs that are meant to be used with your existing dimmer.
Is Dimmer Switch Buzzing Normal?
So all this talk about buzzing, and you must be wondering how normal it is. As I mentioned early on, you will likely hear a buzzing level from almost all dimmers. That is simply due to the way the voltage fluctuates quickly in the alternating current lines.
Unless you have the buzzer feeling hot to touch, you don’t have to worry about anything dangerous.
Usually, when you overload the dimmer, the buzzing is accompanied by a hot switch. That is when you reduce the number of high-wattage bulbs on your fixture. Or opt for lower-wattage bulbs.
However, if you hear a crackling sound, you should get that check out, as it means the wiring is loose and is shorting, creating an electrical arc behind the switch.
It causes burnt contacts and when left untreated, may unfortunately lead to a house fire.
Further reading: Do Dimmer Switches Get Hot?
Mechanical Buzzing Vs Electrical Noise (EMI): What Type Of Buzzing Have You Got?
When we talk about a buzzing noise, it is essential to correctly diagnose the problem at hand. Bussing may be of two types: mechanical and electrical.
Mechanical buzzing occurs when there is something physically vibrating or causing the sound.
And the most common mechanical sounds occur in incandescent bulbs that use a filament to produce light. The constant AC fluctuation causes cheaply built traditional bulbs to vibrate, making a buzz.
If you want to stick to incandescents, usually a simple fix is to get bulbs that have shorter sturdier filaments, such as the standard A19 or a candelabra. Bigger, fancier bulbs have longer, thinner, and more delicate filaments that will end up vibrating with a dimmer.
Electrical noise is caused by electromagnetic interference or EMI. This sound is due to the dimming capability of the switch. The dimming feature occurs when the AC current is being switched on and off at high intervals.
This fast switching causes the electromagnetic field around the wiring to be disrupted. Thus, the EMI sound is produced at times.
That’s why interestingly one lesser known solution for fixing EMI humming or buzzing is to place a strong magnet near the cables of the dimmed light fixture when it is dimmed.
Troubleshooting: When Light Switch Is Buzzing And Light Flickers Simultaneously
Now that you know what to do when the switch is dimming, let’s look at another problem.
Along with buzzing from the switch, your lights may start to flicker! Spooky and psychedelic stuff, but your problem is not ghosts!
The reason for buzzing and flickering may be using dimmer switches with a smart bulb that already has dimming functionality built-in.
When there is a dimmer in a switch and the bulb, the result is not a very pleasant sight.
Since there is a smart chip inside the smart bulb, it does not require an external dimmer switch.
Also read: Do Smart Switches Require Smart Bulbs?
Getting the correct type of bulb with your dimmer switches is very important. Better yet, getting LED compatible dimmer switches along with dimmable LEDs are going to bring you tons of savings per month.
Here is a great dimmer switch (Amazon) that works with LEDs, as well as other bulb types. Once you get that, buy yourself some dimmable LED bulbs (Amazon) and you should not be facing a loud audible mechanical or electrical buzzing sound.
It’s so vital to stay in tune with the electronics around your home. Both for the point of safety and from preventing anything from failing and causing a monetary loss.
Preventing buzzing and humming from dimmers as relatively straight forward.
Have you heard strange buzzing sounds from your switches or fixtures?
Do you use CFLs around the home?
Share your setup with me in the comments below.