In Repair & Maintenance

Dimmable LED flashing: Why it Happens and What to Do

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The most frustrating thing about LED lights, aside from all of the confusing labels on them, is that they are not all dimmer compatible. Dimmable LEDs flash then they are paired with incompatible dimmers. But there’s more to it than that and it can get a little complicated.

Do all Dimmable LED Bulbs Flicker

Not all dimmable LED bulbs will flicker. However, even if everything is perfect, some of them will always flicker. If you pair the bulb with a dimmer that is compatible, you should prevent the flashing.

Why a Dimmable LED Flashes

replacing led light bulb

Dimmable bulbs will flash for several reasons. Sometimes, it just happens. Even with the best brands of dimmable LEDs, you will occasionally get flashing. But dimmable bulbs will flash for three main reasons and all should be ruled out.

It Isn’t a Dimmable LED Bulb

This may seem a bit self-explanatory but a dimmable LED flashes if it isn’t a dimmable LED. Be very careful to read the fine print at the bottom of the bulb to see if it is actually dimmable. It will say if it is just around the base of the bulb.

The Bulb is Dying

While LED bulbs are marketed as lasting decades, they do die eventually. When an LED starts to die, whether or not it is dimmable, it will start to flash. Sometimes it is quick flashes but it is frequently slow flashes. Just enough that it will drive you crazy!

The Dimmer and the Bulb are Not Compatible

A bulb and a dimmer must be compatible for the LED to dim appropriately without flashing. For the most part, Lutron and Leviton dimmers are compatible with most LEDs as long as they are labeled to work on LEDs. You can’t make a non-LED dimmer work for an LED bulb because the voltage just doesn’t go as low as most LED need in order to dim rather than turn off.

led light bulb dimmer compatibility

What if a Dimmer Light is Flickering on High

If your dimmer is on high and an LED bulb is flickering, and not one single quick flash, it is probably due to a dimmer incompatibility. Try the bulb in a light socket that isn’t on a dimmer. If it stops flashing, the dimmer is the problem.

What if a Dimmer Light is Flickering on Low

LED bulbs will typically flicker when the dimmer is set to low because there isn’t enough voltage going to the bulb in order to keep it on at a steady rate. The most reliable way to fix this is to turn the dimmer up slightly. Frequently, you can turn the dimmer up a bit to fix this and then back down and the bulb will be fine.

Best LED Dimmer Switches to Consider

Lutron and Leviton are two dimmer brands that offer excellent compatibility with most LED bulbs. Especially for common brands of LEDs such as Satco, Sylvania, and Phillips, these two brands are great options. They also offer numerous different options for style and switch type so that you can customize your dimmer to your choosing.

Lutron and Leviton offer excellent compatibility

Are Flashing LED Lights Dangerous

Flashing LED lights are not dangerous to the vast majority of the population. The major issue with flashing bulbs is that they are annoying and distracting. However, it is possible that if the bulb flashes at just the wrong pattern and intensity, it could cause a seizure in people with epilepsy.

What if My LED Bulb is Flashing or Strobing Quickly

A short period of quick flashing in an LED bulb is not usually a cause for concern. Even a good bulb with a compatible dimmer may have a short period of quick flashes. 

However, if the flashing lasts for longer than a few seconds, this is a good indicator that the light bulb is dying or your dimmer is incompatible.

The best way to figure out the cause is to try a different light bulb in the socket. If that bulb does okay, the first light bulb is dying and should be replaced.

Why Would LED Bulbs Get Dimmer

dimming led light bulb

LED bulbs show their weakness in their dimming. They get dimmer when they age and when the voltage changes going through the electrical wires that connect to them. Typically, the dimming is so miniscule that most people don’t notice if they aren’t looking for it.

Age

The main reason why LEDs will get dimmer is because they are aging. Rather than an incandescent bulb that is either 100% working or 100% burnt out, an LED just slowly dims over its lifetime. Eventually, the bulb will become so dim that you will feel that the bulb needs to be replaced.

Other Appliances Turning On

Another common reason for LED bulbs to become dimmer is temporary because it is due to a sudden loss of voltage going through the wires. The most frequent cause is other appliances turning on such as an oven or a microwave. Typically, other lights turning on will not be enough to dim an LED.

Conclusion

Flashing LED bulbs are a common problem. Of course, newer bulbs are much better at being compatible with dimmers and are less likely to flash if they are put on dimmers that aren’t perfectly compatible. If you are planning on putting in a dimmer, take a bulb from your home and ask the electrical person to look up the dimmer models that are compatible with it before you install it.