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Why are my Lights Buzzing?

Why are my Lights Buzzing?


When you’re tried, stressed, or just greeted by it first thing in the morning, the that constant droning buzz from your lights isn’t a welcome sound. But why is it there? What’s causing that incessant noise and how can you put a stop to it? Lighting systems, if you zoom out enough, are pretty simple. You have the wires, power source (in the case of your home that would be your circuit breaker or a ballast), controls (light switches and dimmers), and the light bulbs and fixtures themselves. The trouble with noise issues in your electrical system is that any of these points could be the culprit. Different problems cause similar noises, though their location changes depending on what the issue is. Let’s break things down and walk you through how to identify the problem so you know if it’s time to call for a repair or simply change out a light bulb.

Buzzing Electrical Wires

While it can be difficult to detect exactly where the buzz is coming from, if you hear a hum inside the walls whenever your lights are on, then it’s the wires themselves that are humming with electricity. This is most often the case with incandescent lights and is typically due to overloading your lines with high- wattage lamps. If you’ve recently updated with brighter incandescent bulbs, then remove one or two bulbs and see if that helps with the noise. If it does, then switch out your lights for lower wattage bulbs or switch to CFL or LED bulbs to keep the same brightness but decrease the load you’re placing on your home’s wiring.

Humming Dimmers and Switches

Similar to electrical wires, if you hear buzzing coming from a wall switch or dimmer (especially when the dimmer is turned down), you may be overloading the switch. If the switch or faceplate feels hot to the touch as well, you’ve definitely exceeded its maximum rating and should call an electrician to have the switch upgraded or you should purchase lights with a lower wattage. Most wall switches support a maximum wattage of 600 watts (so yes, 6 100-watt incandescent bulbs is too much for a single switch).

Another issue arises when you’re using dimmer switches for your lights. These switches are fantastic when it comes to conserving energy and adding custom light levels to any room but they run into issues with energy-efficient LED and CFL lights. This is because older dimmer switches are TRIAC dimmers that cause a current pulse, providing less power for an incandescent but causing LEDs to switch on and off rapidly. That rapid switching causes both an electric hum and rapid flickering of LEDs and some fluorescent lights.

You should always make sure that any dimmers you own are compatible with the LEDs you’re using. It’s important to purchase a test bulb first when upgrading or to have a trained technician install dimmer switches that work with your LED lights. If you’re concerned that the dimmer in your home is causing the buzzing noise, take the offending lights and plug them into a separate wall switch with no other lights on that circuit. Does the light still buzz and hum? If yes, then it’s likely the dimmer that’s to blame.

Ballasts and Drivers

While incandescent bulbs can operate on AC electricity, LEDs and fluorescents need to have the power regulated more closely. LEDs are typically DC-only devices and fluorescent lights require very carefully controlled power and current levels to maintain their internal electrical arcs. To do this, they both use specific power-regulating devices known as ballasts and drivers (for fluorescent lamps and led lamps respectively).

In many cases, when a tube fluorescent is flickering, buzzing, or humming, it’s due to a power imbalance or an ageing ballast. In most cases, that means the ballast needs to be replaced so you’ll need to call an electrician to have the ballast changed out. Making sure you have a working, quality ballast installed (they have to be paired to the right type of fluorescent tube) is important for both your monthly energy bill and for the longevity of the light bulb itself.

LED drivers are similar in a way. They reduce standard home electrical current into a DC current that is usable by the bulb. They also regulate the maximum and minimum amount of power (or current depending on what kind of driver is being used) to maintain a constant supply to the LED bulb. When the driver is damaged, installed improperly, or simply too old to function properly anymore (drivers typically wear out before the LED bulb does), then the light may begin to flicker or buzz during operation.

Of course, LED bulbs and CFLs still include both ballasts and drivers. They simply include them in the light’s envelope (typically in the base of the bulb). This is why it’s important to buy a test bulb first before you purchase enough to replace the lights in your home. Since those drivers cannot be replaced without replacing the entire light bulb. Buy a test bulb, see if it works in your home, and then replace the remaining lights.

Light Bulb Differences

One final note about noisy lights: Never mix and match light bulbs. Yes, they can be used together but they’re more likely to interfere with each other if you’ve mixed lights, especially if those lights are on a dimmer. Make sure that each circuit consists solely of LED, fluorescent, or incandescent bulbs. If you hear buzzing coming from your lights and notice that you have more than one type of bulb installed, try removing the odd bulb and see if the sound persists. If it doesn’t, replace the bulb with more of the type that are already installed on that circuit.

If you would like more information about electrical repairs, maintenance, or wiring services from 24/7 Electric, please call us at 587-315-1361 in Calgary or 778-557-1519 in Victoria, or complete our online request form.


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