Advice from an industry expert on how to prevent your LED lights from flickering, buzzing, or burning out, as well as information regarding the dimming of LEDs.

LED Troubleshooting

LED Troubleshooting

It is estimated that LED lights should survive for more than ten years before they need to be replaced. LED lights are an environmentally friendly option for lighting your home. As a result of advancements in technology that enable manufacturers to produce bulbs that are brighter and practically comparable in appearance to conventional light bulbs, an increasing number of consumers are making the move.

LEDs, on the other hand, operate in a different way than traditional light bulbs, which may result in some difficulties when attempting to install them in older circuits. On this page, we take a look at some of the most typical problems encountered when switching to LED bulbs, such as LED lights flickering, buzzing, or not dimming properly, and we discuss how these problems can be resolved.

How to prevent LED light bulbs from failing prematurely

Prevent LED light

Prevent LED light

LEDs are expected to have a far longer lifespan than traditional lighting options such as halogen or incandescent bulbs. Some manufacturers claim that their product will last for up to 25,000 hours, which is equivalent to more than 20 years if it is used for three hours every day.

In 2015, we conducted an investigation on the LED lifetime promises made by manufacturers by operating hundreds of bulbs continuously for up to 15,000 hours and by turning them on and off 10,000 times. Because more than 80 percent of the LED bulbs we evaluated continued to function after the experiment, we believe that you should anticipate LED bulbs to last for a considerable amount of time in your house as well.

Putting LED light bulbs into light fittings that already contain some incandescent or incandescent-style light bulbs is, according to the professionals in the relevant industry that we consulted, one of the most typical causes of premature LED burnout.

In comparison to traditional light bulbs, light-emitting diodes (LEDs) are engineered to efficiently dissipate the little level of heat that they produce. However, they may have difficulty surviving in extremely hot weather. It is possible for them to fail sooner than expected if they are placed in an enclosed fitting or in close proximity to light bulbs with a significantly higher power.

Rather than replacing individual bulbs as they burn out, the most effective strategy is to change all of the bulbs in a fixture at once. Because of this, the possibility of the device overheating will be greatly reduced, and the light output will also appear more consistent.

Fixing LED lights that buzz or flicker is covered here.

Buzz or Flicker

Buzz or Flicker

LED lights can flicker or buzz if the current (the flow of electrical charge) doesn’t remain constant. There are a lot of plausible causes for this:

1. Incorrect dimming set-up

This creates flashing and buzzing, and is frequently down to using the improper dimmer switch. Your property is likely to feature a ‘leading edge’ dimmer. These are meant to smoothly dim old-style lights on a circuit with a range typically from 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 move from 4 × 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 considerably lower power and will better manage your lights and reduce 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 (add up the total wattage of all of the bulbs in the circuit you are dimming) (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 lamps.

LED dimming checklist:

Buy LED bulbs that claim they are dimmable. Check whether your dimmer switch is suited for LEDs, then calculate the overall wattage in the circuit to check if it’s in the proper range. Switch to a trailing edge dimmer if needed. Check the website of the company that makes the LED bulb, as they might have some unique recommendations. It is best to avoid using both LEDs and traditional light bulbs (incandescent, halogen, or compact fluorescent light bulbs) in the same fitting. For optimal consistency, utilise LED bulbs that are the same, both in terms of brand and specification, within a single fitting. The purchase of multipacks, particularly of LED GU10 spotlights, can frequently result in cost savings.

2. An appliance with a higher power rating that is connected to the same circuit

Flickering can occur with low-power LED lights if an equipment with a high power draw, such as an electric fan, is connected to the same circuit as the bulbs. This circumstance occurs seldom. Traditional light bulbs require a significantly higher voltage (the force needed to make electricity flow), whereas LED bulbs require a much lower voltage, which is why LED bulbs contain inbuilt drivers (transformers) to reduce the voltage that is applied to the LED bulb.

In the scenario presented below, turning on the fan could result in a brief increase in the circuit’s voltage. The flickering that you witness is a result of the drivers in the LED bulbs adjusting the voltage so that it is appropriate for the LED. The most effective solution to this issue will be to have your electrical circuits inspected by a licenced electrician.

3. Loose connections

This is one of the most typical reasons for flickering that might occur. If you have determined that no other potential causes are at play, it is in your best interest to have an electrician examine your property to determine whether or not this is the issue. If you believe you might require the services of an electrician, head on over to Which? Trusted Traders to see which suppliers come highly rated.



LEDs and DAB radio interference

All electrical appliances emit electromagnetic interference (EMI) (EMI). This can, in rare situations, interfere with a DAB radio signal. EMI is carefully controlled within the EU, therefore if you are having this problem in your house, check that your LED bulbs have a CE label, and replace them immediately if they don’t.

After hearing from Which? members who had encountered this problem, we performed a major test of cheap LED light bulbs seeking for lights that interfered with DAB radio.

We didn’t identify a single bulb where this was a problem. If you are one of the unlucky people experiencing this, it could be that the issue isn’t the bulb, but your electrical set-up or your dimmer switch. To remedy this problem, we would recommend visiting an electrician to diagnose the precise cause, before you fork out further money on new lights or LED-compatible dimmer switches.

Lights shining

Lights shining

Lights shining, even when switched off

Some light switches let through a little amount of electricity, even when switched off. This was never visible with old-style bulbs (although it would still effect your costs) because the power was never adequate to appear as light.

However, LED lights have such low power that a slight ‘leak’ of electricity like this can be enough to make them shine. This problem suggests either an issue with the electrical circuit, or very inexpensive and badly built LED lights. If you have this problem you should ask an electrician to investigate.

Other LED bulb difficulties

LEDs have come a long way in recent years, however other challenges you can find are:

Narrow beam angle – producing dark areas in the room

Inconsistent light output – bulbs of varied colour or brightness giving a patchy light impact

Sudden rather than gradual lowering of light – generating a less seamless impact

LED bulb difficulties

LED bulb difficulties

Our LED research

In 2017, we asked 1,728 Which? members to tell us about any LED difficulties they’d experienced in their homes. We then recruited industry experts, and our top Trusted Trader electricians, to shed some light on what might be causing each issue – and how to remedy it.

According to our poll, 90 percent of members who have LEDs in their home are delighted with their bulbs and the quality of light they create. More than half haven’t faced any troubles at all when fitting their LEDs. Early failures (28 percent ), flickering (12 percent ), buzzing (5 percent ) and radio interference (2 percent ) were the main problems encountered.