LED Tips & Tricks - How to fix flickering or buzzing LED lights？
LED bulbs can flicker or buzz if the current (the flow of electrical charge) doesn’t remain constant. There are a number of possible causes for this:
1. Incorrect dimming set-up
This causes flickering and buzzing, and is usually down to using the wrong dimmer switch. Your home is likely to have a ‘leading edge’ dimmer. These are designed to smoothly dim old-style bulbs in a circuit with a range typically between 200W to 1,000W.
This is a problem for LEDs that don’t need anything like that level of current in the circuit. For example, if you switch from 4 x 60W bulbs in a circuit to 4 x equivalent brightness 9W LEDs, your total wattage has gone from 240W to 36W.
‘Trailing edge’ LED dimmers (from £15) dim on a much lower wattage and will better control your lights and avoid flickering. Make sure you check the wattage rating of the trailing edge dimmer to make sure it suits the wattage of the lights in the dimmer circuit (count up the total wattage of all of the bulbs in the circuit you are dimming). Choosing a dimmer with too low or high a range will mean that you can't smoothly dim your new LED bulbs.
- LED dimming checklist: Buy LED bulbs that state they are dimmable.
- Check whether your dimmer switch is designed for LEDs, and calculate the total wattage in the circuit to see if it's in the right range.
- Switch to a trailing edge dimmer if needed. Check the LED bulb manufacturer's website as they may have specific recommendations.
- Avoid mixing LEDs and old-style (incandescent, halogen or CFL) bulbs in the same fitting.
- Ideally, use identical LED bulbs (ie the same brand /spec) in one fitting for consistency. Buying multipacks, especially of LED GU10 spotlights, is often cheaper, too.
See our top picks if you're after new LEDs in our round-up of the best LED light bulbs.
2. A high-powered appliance in the same circuit
This is rare, but if an appliance with a heavy power draw, such as an electric fan, is on the same circuit as low-power LED bulbs, it can cause flickering.
LED bulbs require a much lower voltage (the force needed to make electricity flow) than traditional bulbs, so they have internal drivers (transformers) to reduce the voltage to the LED bulb. Turning on the fan, in this example, can cause a momentary voltage surge in the circuit.
The flickering you see is the drivers in the LED bulbs adjusting the voltage to suit the LED. Getting an electrician to examine your circuits will be the best way to fix such a problem.
3. Loose connections
This is one of the most common causes of flickering. If you've eliminated other possible causes, it's best to get an electrician to assess if this is the problem in your home.