LED lights are an energy efficient way to light your home, and they should last more than a decade before they need to be replaced.
More and more people are making the switch, as technology has improved to allow for brighter bulbs that look nearly identical to traditional light bulbs.
However, LEDs work differently than older light bulbs, and this can cause some problems when installed in older circuits.
On this page, we look at some of the most common issues we encounter when switching to LED bulbs — like LED lights flickering, buzzing, or not dimming properly — and how to fix them.
How to stop LED lights from failing early
Compared to older halogen or incandescent bulbs, LED lights should last a lifetime. Some have lifetime claims of up to 25,000 hours—more than 20 years if you use them for three hours a day.
We investigated LED lifespan claims in 2015, letting hundreds of LEDs run for up to 15,000 hours, and also turning them on and off 10,000 times. Over 80% of the LEDs we tested were still working after this, so we think you should expect LEDs to go the distance in your home as well.
One of the most common causes of premature wear and tear on LEDs, according to the industry experts we spoke to, is placing LEDs in light fixtures that still contain some old light bulbs.
LED lights are designed to dissipate the relatively small amount of heat they generate, compared to older bulbs. However, they can experience very high temperatures. If they are placed near light bulbs that are much higher wattage, or in closed fixtures, this can cause them to fail early.
The best way to prevent this is to replace all bulbs in fixtures at once instead of blowing them out. This will significantly reduce the risk of overheating and the light output will look more uniform as well.
How to fix flashing or buzzing LED lights
LEDs can blink or buzz if the current (the flow of electric charge) is not kept constant. There are a number of possible reasons for this:
1. Incorrect dim setting
This causes flashing and buzzing, and is usually due to the use of a faulty dimmer switch. Your home likely has a faded “leading edge.” These bulbs are designed to smoothly dim old-fashioned bulbs in a circuit typically with a range of 200 watts to 1000 watts.
This is a problem for LEDs that don’t need anything like this level of current in the circuit. For example, if you switched from 4 x 60 watt bulbs in a circuit to 4 x 9 watt equivalent brightness, your total wattage increased from 240 watts to 36 watts.
LED ‘Rear Edge’ dimmers (from £15) dim much less wattage and you’ll better control the lights and avoid flickering. Be sure to check the wattage rating of the trailing edge dimmer to make sure it matches the wattage of the lights in the dimmer circuit (calculate the total wattage of all the lights in the circuit you’re dimming). Choosing a dimmer with a very low or high range means that you cannot smoothly dim new LED bulbs.
LED Dimming Checklist:
- Purchase LED bulbs that state that they are dimmable.
- Check if your dimmer is designed for LEDs, and calculate the total wattage in the circuit to see if it’s in the correct range.
- Switch to a faded back edge if needed. Check the LED lamp manufacturer’s website as they may have specific recommendations.
- Avoid mixing old LEDs and bulbs (incandescent, halogen, or CFL) in the same fixture.
- Ideally, use identical LED bulbs (i.e. same brand/spec) in one fixture for consistency. It’s often cheaper to buy multiple packages, especially GU10 LED spotlights, as well.
2. High power device in the same circuit
This is rare, but if a device with a heavy power draw, such as an electric fan, is in the same circuit as the low-power LEDs, it can cause a flicker.
LEDs require much less voltage (the power needed to flow electricity) than conventional lights, so they have internal motors (inverters) to reduce the LED’s voltage. Running the fan, in this example, can cause a momentary voltage surge in the circuit.
The flashes you see are motors in the LEDs adjusting the voltage to match the LED. Getting an electrician to check your circuits would be the best way to fix this problem.
3. loose connections
This is one of the most common causes of palpitations. If you have ruled out other possible causes, it is best to hire an electrician to assess if this is the problem in your home.
If you think you might need an electrician, head toto our recommended providers.
LEDs and DAB . radio interference
All electrical devices emit electromagnetic interference (EMI). This can, in rare cases, interfere with the DAB radio signal. EMI is tightly controlled within the European Union, so if you’re experiencing this problem in your home, make sure your LED lights are CE marked, and replace them immediately if they aren’t.
After hearing from which? Members who have experienced this issue, we ran a big test of cheap LED light bulbs for bulbs that interfere with DAB radio. We didn’t find a single bulb so this was a problem. If you are one of the unlucky people to have experienced this, the problem may be not the lamp, but the electrical setting or the dimmer switch.
To solve this problem, we recommend consulting an electrician to diagnose the exact cause, before spending more money on new bulbs or compatible LED dimmers.
The lights glow, even when turned off
Some light switches allow a small amount of electricity to pass through, even when they are turned off. This was never obvious with old bulbs (although it will still affect your bills) because the power was never enough to show up as light. However, LEDs are so low power that a small leak of electricity like this can be enough to make them glow.
This problem indicates a problem with the electrical circuit, or LED bulbs that are very cheap and poorly manufactured. If you have this problem, you should ask an electrician to investigate.
Other LED bulb problems
LEDs have come a long way in recent years, but other problems you may encounter are:
- narrow beam angle – Cause dark spots in the room
- inconsistent light output – Bulbs of varying color or brightness cause intermittent light effect
- Sudden dimming of light instead of gradual dimming – Create a less smooth effect
Our search for LED
In 2017, we asked 1,728 which one? to tell us about any LED problems they have encountered in their homes. Then we consulted with industry experts, top electricians and top trusted dealers, to shed some light on the cause of each problem – and how to fix it.
According to our survey, 90% of the members who have LED lights in their homes are happy with their bulbs and the quality of light they produce. More than half had no problems at all when installing their LED lights. The main problems encountered were premature failure (28%), flickering (12%), buzzing (5%) and radio interference (2%).