Why do my LED lights buzz when dimmed?

LED lights buzz when dimmed because of incompatibility between the LED driver and your dimmer switch, causing electrical interference that creates audible vibrations.

The buzzing sound you're hearing is actually the LED driver (the electronic component that regulates power to the LED) struggling to work with your dimmer. Unlike traditional incandescent bulbs that dim smoothly by simply reducing voltage, LEDs require precise electronic control. When there's a mismatch between your dimmer and the LED's requirements, it creates electrical "noise" that manifests as that annoying buzz or hum.

Most buzzing issues stem from using older dimmer switches designed for incandescent bulbs. These dimmers use a technology called "leading edge" or "TRIAC" dimming, which rapidly switches power on and off. While this worked fine for incandescent bulbs, it can cause LED drivers to vibrate and buzz. The cheaper the LED bulb, the more likely it is to buzz because budget LEDs often have lower-quality drivers that are more sensitive to electrical interference.

In Ottawa homes, this is especially common in older houses where homeowners have upgraded to LED bulbs but kept their original dimmer switches. Under the Ontario Electrical Safety Code, replacing dimmer switches requires proper electrical knowledge and may need an ESA permit depending on the scope of work.

The solution is usually replacing your dimmer with an LED-compatible model. Look for dimmers specifically labeled "LED" or "CFL/LED compatible." These use different dimming technologies like "trailing edge" dimming that work better with LED drivers. Quality LED-compatible dimmers from brands like Lutron or Leviton typically cost $30-80 each, compared to $10-20 for basic incandescent dimmers.

Safety considerations are important here - if the buzzing is accompanied by flickering, heat, or burning smells, shut off the circuit immediately and call a licensed electrician. These could indicate dangerous electrical issues beyond simple incompatibility. Also, some buzzing can come from loose connections in the electrical box, which poses a fire risk.

For the best results, choose higher-quality LED bulbs that specifically state "dimmable" and list compatible dimmer types. Cheap LED bulbs often lack proper dimming circuits and will buzz regardless of your dimmer switch.

If you're experiencing persistent buzzing issues or need dimmer switches replaced throughout your home, Electrical Ottawa's licensed electricians can assess your specific situation and recommend the best LED-compatible dimming solutions for your needs.

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