Dimmer switch is buzzing at one location but not at another


First let me just say, that I noticed that you did not ask, How do I stop a dimmer switch from humming?, but rather WHY is it buzzing (especially, here- not there).

Essentially, your dimmer is also creating or acting like a speaker, because it is physically causing air to vibrate, which is detected by your ear... in other words, sound is created by moving air back and forth. A speaker is made by inducing a magnetic field in an object (like a coil or a bulb filament) which exerts a physical force upon the (induced) object causing it to move and by default, move the air. The range of human hearing is 20 to 20,000 Hz and the frequency of the electricity in a residence is 60 Hz.

The reason it is happening in the dimmer is the same reason as the light bulb; some piece of the dimmer or a neighboring conductor is physically vibrating.

Why it is only in the one spot has to do with something called harmonics... and there is a long physics lecture involved. But in short,...

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I installed a dimmer switch in my washroom and it's making a buzzing noise. The more I increase resistance/rotate the dimmer clockwise, the louder it gets.

The humming seems to be coming from the common wire, not from the light fixture, live wire or from the mechanism within the dimmer itself.

The dimmer switch is advertised to hold up to 600w and I'm currently using 340w.

I tried to remove some of the lights and the noise persists.

The one thing I did notice is that the common wire isn't exposed or attached at the end, a section of the wire has been stripped at that's what the original switch was attached to.

How can I lessen or completely rid myself of this humming noise?

Edit: I've since replaced my Leviton rotary dimmer with a high end Lutron sliding dimmer and the problem still persists, at the same loud...

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just noticed that a light switch (mechanical, not a dimmer; 220v 50hz) is buzzing at audible volume (can hear in 20cm), when both keys are on (first: traditional lightbulb, second: 23w energy saving bulb - with all that electronics inside).

Didn't opened the switch so dunno how it is wired (common phase.. or a common ground - if an installation point is powered by two wires, a drunk specialist may have used them the wrong way), it is known that this connection is split from wall sockets/main room lightning (yes, two switches outside the house!).


pressing key 2: energy-saving bulb enabled, no sound 2, then 1 (normal bulb): sound. 2, ..some time, 1: sound 1, 2: sound sometimes, no sound at any combination.

Guessing that a bulb is possibly broken and sends a high-freq noise that forms an arc.. Unfortunatelly can't get a single normal bulb today to test if it forms a noise,...

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Dimmer switches have a power rating that indicates the safe levels of operation. If you are running too many, or too high wattage bulbs for the switch, this might be causing the buzzing. It would also be getting warm, or hot after being on for a bit. You'd be able to feel it with your hand on the switch and on the wall just above the switch. There should be a sticker or a stamp somewhere on the back or side with the wattage rating. Just add up the total wattage of all the bulbs and compare it to the rating. Also, check to make sure the bulbs you are using are compatible with dimmers. Lastly, lower end switches will buzz more often than better quality switches. They even advertise some of them as silent or quiet. One of these would undoubtedly silence the buzz.
Good luck.

Source(s): General Contractor
25yrs experience...

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Some dimmers and light bulbs are more prone to buzzing than others.

My dining room chandelier is operated by a dimmer switch, but every time we dim the lights, there’s an annoying buzzing or humming sound. What’s wrong and how can we fix it?

Talk about mood lighting! If you don’t like serving dinner with a nice buzz, the good news is that you can probably fix the problem either by replacing the bulbs or the dimmer switch itself.

Dimmer switches work by chopping up the AC current flowing between the switch and the light. Rather than literally “dimming” the light itself, these switches actually cause the current to undulate or flicker extremely rapidly, so that to our human eyes, it appears that there is less light. The interrupted current can produce a vibration in the electromagnetic field within the light bulb filament or within the switch itself, which can cause a humming or buzzing noise.

Here are some steps you can take to reduce or eliminate the...

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Finding the perfect lighting balance in every room of your home is as much an issue of function as it is of decor. Sometimes standard lights are too bright, but no lights make the room feel like a cave. The use of a dimmer switch fixes these problems as it allows users to manually control the level of lights in a room. However, like any electrical element in your home, dimmer switches do not always operate perfectly. Knowing how to troubleshoot three common dimmer switch problems circumvents the need to spend a lot of money on an electrician and restores your 'perfect' lighting with the least hassle.

Installation Problems

The most likely time that homeowners encounter problems with their dimmer switch is when they complete the installation of one to operate their lamp or ceiling lights. There are several common issues with dimmer switch installation, which includes dimmers that do not work at all and lights that simply flicker rather than project steady...

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A dimmer switch can help create ambience by allowing you to get your lighting level just right. Or it can destroy ambiance by making it sound as if your chandelier doubles as a boarding house for cicadas. This buzzing noise is a common unintended consequence of dimmer switches, but it's not a necessary consequence. If you need help making sure the effects of a dimmer switch are seen, but not heard, here are a few possible solutions.

What's All the Buzz About?

It's a common, and understandable, misconception that dimmer switches simply reduce the voltage of the electricity that goes to a light fixture. In fact, the voltage doesn't change. Instead, the dimmer cycles the electricity on and off very rapidly, far faster than the human eye can follow. So while what's really happening is that the lights are turning on and off, your brain interprets it as the light being dimmer. This rapid cycling can cause the filaments of your light bulb to vibrate, and it's this vibration...

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The first thing I'd do is try to find a model number on your dimmer under the faceplate, and determine if it is intended to be compatible with LED, or least dimmable CFL bulbs. If not, it probably should be replaced. At 10 years old, I suspect it is not specifically designed to be LED compatible, although some LED bulbs might still work with it.

Each dimmer switch seems to work a little different, and each LED bulb has a different driver that converts the AC power, possibly distorted by the dimmer, into smooth DC power the LED's need. Not all of them interact well together. It's a little more complex than the voltage, and frankly, is still a bit of a crapshoot with LED's. If they flicker for a bit when you first change the dimmer setting, and then stabilize, I'd be inclined to call that a win.

If they flicker continuously, different models of either might resolve it. From discussions elsewhere, I don't think Feit rank among the better bulbs for dimming, but a dimmer...

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I would seem to be coming from a couple of places. When I sit down about five feet from the amp (my usual position), the hum is the least noticeable. When I stand up and move about eight feet from the amp towards a small wall that is in the centre of the hall (it contains the heating duct that goes upstairs) it gets much worse, and I believe there is wiring inside there as well. Also, if I move towards the stereo, which is close to a lamp that has a compact florescent in it, and there is also a cordless phone with answering machine it gets worse.

I checked the light with the compact florescent, it didn't make any difference to the hum when I turned the light off and on. There is a lso a dimmer switch in the living room which controls the light over where I sit. However, it is basically never on. The other day I turned it on, with the amp on and the guitar around my neck. If I held the the dimmer knob with it partially on, I could hear a bit of noise, a buzz, but a different...

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Dimmer Switch TIPS

DEAR TIM: I would like to install several dimmer switches to control light output. Do I need special wiring to accomplish this?

Older dimmers I have used scared me because the switch is very warm to the touch when they operate. Are these things a fire hazard?

Are there specialty dimmers for individual lamps or fixtures?

Are there some lights that do NOT WORK with dimmers? Jo Anne C., Edison, NJ

DEAR JO ANNE: Light dimming switches are not only very safe, but the variety of sleek and efficient dimmers you can purchase today is outstanding.

Fire Hazard Is Real

In my opinion, the only fire hazard you might introduce to your home while installing one would be failure, on your part, of reading and following any enclosed instructions. I have installed dimmer switches for years and not one has ever caused an electrical fire.

The most common fire caused by dimmer switches is putting too much power through them....

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I have never tried to buy a 4 way dimmer, so I don't know if they exist or not. However, if you use a standard 4 way switch, and get a 3 way dimmer, you could dim it from one location with one of the 3 way switches.

Should all 4 way switches have 4 connector screws?

Yes, plus a 5th screw for a ground wire, if it is a grounding switch. Not all switches have ground terminals on them. If it does, that screw is typically green.

in the circuit I want to change, it looks like all of the switches have 3 screws, plus ground

Hmm, that would be an odd setup for a lighting circuit that is controlled by 3 switches. There is another way to wire a 3 way setup, called a "Michigan 3 way". But I've been told it's illegal, because it isn't safe. I once had an old time electrician draw it out for me, but I don't remember what the schematic looked like. It's possible you have that type of setup at your place.

so therefore, a typical 4 way circuit should have 3...

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Dimmers do make a noise although differnt makes and set-ups can be better or worse than others. I don't use LAP accessories, so have no experience of them, but generally the major brands like MK, Crabtree etc are better.

In an attempt to cure the problem firstly you should check that the Low Voltage transformers that were installed are compatibale with the dimmer. Some LV transformers are not capable of being dimmed (although the majority you buy these days are). If the transformers you have are not dimmable then this could cause buzzing, as the voltage is reduced (turning the dimmer knob) which in simple laymans terms causes a conflict between the electronics in the dimmer and the electronics in the LV transformer.

If the buzzing seems worse when the lights are not at full brightness? This could be a load issue. By that I mean that the combined wattage of the LV lamps (i.e the load) is not properly matched to the dimmer. For example if you have 4 x 50w lamps then the...

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Light bulbs

Why do the bulbs of a certain fixture burn out a lot?
When a fixture cannot dissipate the heat of its bulbs, it takes a toll on the bulbs and on the fixture's sockets and wires. If the lights are ones that are left on a lot -- like outdoor lights left on all night -- then the bulbs may be living their full life but will simply have to be changed more often than others. But...

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There is nothing more obnoxious than lying down to sleep, resting comfortably under your ceiling fan, and then all of the sudden experience a buzzing noise. If you are having this kind of trouble with your ceiling fan, following are some recommendations for correcting the problem. If for any reason you are running your fan without blades or missing one or two blades, you could be hearing a buzzing noise. While you would think that running a fan with the blades on is common sense, you would be surprised.

If your ceiling fan is operated while using a dimmer switch, it is possible that this is the cause of the buzzing. Another cause could be due to your fan speed control, trying to control a fan with numerous speeds. When shopping for a ceiling fan, make sure it has a three-way or four-way wall control and nothing more. If you cannot tell how much of the buzzing is coming from the fan itself, you can remove the wall switch and supply live power...

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I've got an issue that I can't come up with a logical explanation. Last week I sent my service tech to address a warranty issue with a "buzzing" GFI. I told him to just check wiring and replace GFI. This week they call back and tell my that all GFIs are buzzing. I go out and sure enough, they are all making a low buzzing sound. Can't say it was a "bad batch" since one is brand new. Some are buzzing louder than others. One of the GFIs is a dedicated outlet right next to the panel, maybe 4' of wire.

House 10 months finished.
200 amp back to back with underground service.
No overhead lines in neighborhood.
All connections verified good at recepts and panel. Have not pulled meter.
P&S brand.
Sound stops when tripped.
Sound stops on all half the time, other half they are all buzzing. Time of day doesn't seem to be a factor, it's random.
Voltage checks out.

Thank you for any...

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