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LED Light Flickering: Why do LED Lights Flicker + How to Fix It

Nothing makes space go from splendor to squalor quicker than a flickering bulb.

It’s one of those things that you want to get fixing right away.

LED lights are either on or off. When you switch them off, the light disappears instantly, unlike with old incandescent bulbs. When the LED bulb malfunctions and turns on and off rapidly, that’s when you can see flickering.

There are several potential causes for why your LED light flickers. It may be due to loose or incorrect wiring, incompatible dimmer switches, or faulty bulb components such as a defective LED driver.

Here’s a quick rundown of what’s included in this guide to LED light flickering:

  • Reasons your LED lights could flicker without a dimmer switch
  • Why a dimmer switch can cause flickering LED lights
  • Reasons flickering persists with the light switch off
  • What it means when all LEDs in your home are flickering
  • Whether flickering lights are a fire hazard
  • How to fix flickering lights

3 Possible Reasons Why LED Light Bulbs Flicker (No Dimmer)

graphics why my LED lights flicker
There are three main reasons that your LED lights can flicker if they aren’t on a dimmer switch:

  • Problems with the bulb itself
  • Problems with the electrical wiring
  • Problems with your electrical current

Problems with the LED bulb

The reason a single LED bulb is flickering is often because the bulb itself is faulty.

Usually, it’s because the driver – the chip that controls the bulb – has been damaged due to heat from the other internal components. Most of the time, it will be because of a swollen or bulging capacitor.

Here’s a video demonstration of how to swap out a bad capacitor in your LED lamp.

Problems with the wiring

Electricians clears wire for electricity installation

Sometimes a short wire length within the light fixture could be at fault. It is a good practice to have all wires at least 6” long.

Loose wires connecting the bulb, fixture, and switch could all be reasons for a sudden onset of flickering light bulbs. You’ll need to fix this faulty wiring to get the light working.

Moving away from the light fixtures and into your electrical panel, loose wiring in the circuit breaker is a common occurrence and a reason for a flickering light.

So check your LED light bulbs to make sure there’s plenty of wire and that there are no loose connections.

Then check the circuit breaker to make sure there isn’t a loose connection point there. If there is, then it will likely be affecting your whole home’s electrical system for your lights – multiple lights would have visible flicker.

Problems with your electrical current

Another thing that can cause flickering is the power factor, which is the efficiency of other appliances in the circuit.

For example, having incandescent light bulbs connected to the same circuit as LED lighting will make the LED flicker. The reason is that a traditional bulb uses 100% of the needed energy, most likely 60W.

Having a couple of incandescent bulbs will quickly draw all the power, leaving next to nothing for your LED lamps, which will make them flicker due to the lack of power.

Dimmer Switch: Why Do My LED Lights Flicker On A Dimmer?

turning the dimmer switch
Since you now know that LED tech works in binary on/off state, you can understand better why it runs into trouble when hooked up with old dimmers meant for incandescent bulbs, which evenly changes the amount of current going to the bulb.

An incompatible dimmer switch wired to a newer LED light fixture or bulb will produce a flickering problem – there will be an uneven flicker frequency (on/off at irregular intervals).

So, can LED lights be used on a dimmer switch?

In short, yes. Often the issue of flickering LEDs can be as simple as using non-dimmable LED bulbs on dimmer switches. It is a simple but commonly overlooked problem. The fix is also simple, just replace non-dimmable LEDs with dimmable LED bulbs.

Here is an example of flickering LEDs in my living room. Note that these are non-dimmable LEDs installed on the dimmer.

flickering non-dimmable LED in the fixture
The easy fix is just to turn the dimmer to 100% to correct the light output. This will make sure the lights get all the power they need.

But if you want to be able to dim them, you’ll need to swap to dimmable LED bulbs and a compatible switch.

Don’t be tempted by the other easy solution of switching back to traditional bulbs. You’ll lose all the efficiency benefits than an LED light bulb gives you since they use so much less energy.

Instead, just correct the dimmer compatibility to resolve the flickering issues properly.

Why Do LEDs Flicker Even When Lights Are Off?

replacing the bulb

Some LED bulbs will flicker even when switched off.

Not a faint after-glow for a few seconds or minutes, but a dimmed light that stays on, or a full flicker effect occurs even after the switch is closed. It’s due to residual power in the capacitor.

In the olden days, this would be considered “magic”- but now we know that it’s just science tricks most people know about.

All LED bulbs with this problem have one thing in common: fancy switches.

Basically, switches have some extra features like a dimmer, WiFi control, night light, or even a tiny indicator light.

These smart dimmer switches need some standby power all the time for the features to work.

But this is where faults can arise. The trouble lies in the circuitry and incorrect wiring connections in the existing wall switch with the LED light bulb.

Due to this incorrect wiring, the switch may not utilize the neutral wire.

The LED is on the negative wire, which leads to capacitive coupling and a build-up of residual power in the capacitor.

With this stray capacitance and current leakage, enough voltage can accumulate to make the LEDs glow or flicker.

You can check this by touching a one-touch tester to one of the two connections in your LED lamp socket with the switch off.

The stray current passing through the tester’s body will complete the circuit, and the light should flicker.

So that was the science behind the case of the peculiar flickering light. In the right kind of party, it can potentially hold an audience captive.

Also read: Why Do LED Lights Flicker On The Video?

Why Are All My LED Lights Flickering In The House?

flickering table lamp

When only one or a few LED lights in your home are flickering, it’s easy to spot where potential problems might be. But when all your LED lights are flickering, it can be more challenging.

There are two potential reasons why all your LED lights are flickering:

  • Your entire house has dimmer switches (in this case, go back to the solutions I mentioned above)
  • A sudden drop in voltage

Usually, flickering lights in the entire home is caused by a sudden drop in voltage.

This can normally be attributed to a high-powered or large appliance on your home circuit.

Because these appliances require a lot of power supply, especially with a surge when they first switch on, the reduced voltage in the circuit can cause your bulbs to start adjusting to the lower power levels, which makes LED flicker.

Most modern homes have light fixtures on different circuits to wall outlets or dedicated car chargers, which should negate this issue, but it’s one to check.

It may not even be your home causing the problem. Most homes share a transformer with neighboring properties.

If you have that one person on your street who likes to turn on every appliance at once, they might be acting as a drain on the whole neighborhood’s electrical system.

If the problem isn’t a surge due to high-demand appliances, the light bulbs in your home could be flickering due to damage to the main power supply.

If you’ve had bad weather and the problem has only just started, it’s likely that a fallen tree or similar cause has damaged the nearby wires. Call your power company if that’s the case.

Are Flickering LED Lights Dangerous?

Short circuit, burnt cable

 

Flickering lights can be dangerous if left unchecked. As you know, the common cause of a flicker can be loose wiring.

Consequently, loose wires in circuits are a leading cause of house fires due to the high resistance to current flow.

When you can see your LED lighting starts to flicker, you know for sure that it’s time to take corrective measures.

Home/office safety is a top priority when working with electrical components and troubleshooting. If you are not experienced in electrical work, it is imperative to call in a lighting specialist to get things checked out.

It’s definitely not to be taken lightly.

Flickering LED lights can also cause some of these other problems:

Turn off the faulty light bulbs, and keep the circuit off until you can get professional help.

What is Invisible Flickering And How to Spot It?

Sometimes, bulb flicker cannot be detected by the human eye but is still registered by your brain, affecting it negatively. It’s more common in low quality LEDs.

A simple way to locate flickering bulbs not seen by your own eye is to point your phone’s camera at the bulb. If you see a series of light and dark bands moving slowly across the screen, it means your bulb is imperceptibly flickering.

The good news is that you have an answer for any headaches, impaired vision, and lack of focus you might have been facing, as these are all consequences of a flicker that you can now fix.

The bad news is that you can’t just leave it alone – not fixing it can be a cause of an epileptic seizure in someone with the illness, or accidents resulting from a lack of concentration.

Not to mention other fire hazards associated to faulty lights.

How To Stop and Prevent Flickering in the Future?

Electrician installing a dimmer switch in a wall socket

To prevent LED lights from flickering, start by troubleshooting and eliminate possible problems. The easiest problem to check is the bulb, so start there before checking wires and switches.

Fixing a faulty bulb

To check if your LED bulb is causing flickering, follow these steps:

  1. Twist the LED bulb and make sure it’s not simply a loose bulb giving you all this trouble
  2. While you’re at it, wipe the inside of the bulb’s socket and any LED fixture, removing dust and ensuring better contact
  3. Swap out the LED bulb with any other bulb.

If the new one works well, you know the fault was in the bulb.

If the bulb is at fault, instead of simply tossing it out, maybe open it up and see if you want to try and DIY-fix it, as one does. A common culprit, as mentioned earlier, would be a swollen capacitor.

Often, LED lighting is as good as its capacitor. You can replace this broken capacitor with a 50-cent good-quality one that withstands higher temperatures and buy yourself a few extra years out of a bulb otherwise gone cuckoo.

If the capacitor looks fine, it could be the driver. Most modern LED bulbs have something called a constant current LED driver already installed on the chip inside, which regulates the alternating current for the bulb.

This is harder to replace manually and may just warrant a new bulb.

Fixing dimmer switch issues

If your LED bulb is flickering because of a dimmer switch, you need to:

  1. Read the labels for the boxes to see if the lights and dimmer are compatible
  2. If you can’t find the boxes/there’s no info about compatibility, check online using the model numbers
  3. Toggle the dimmer switch to find a working level – but this isn’t ideal, because anything lower than 50% will usually kick in the flicker

If these haven’t solved the issue then try these products to help prevent and stop LEDs from flickering:

With smart LED bulbs there is no need for an old dimmer or aged wiring to remain. It is a complete solution of dimmable light in itself, among other features like changing the color.

Fixing a voltage issue

If there is no dimmer and the bulb is not at fault, you can fix your LED lights flickering by:

  1. Moving any high-power appliances to their own circuits, and not on the same circuit as your lighting
  2. Buy a voltmeter to check the current running into your home/office is adequate.

Voltage into the house shouldn’t average more than 120V.

For all these extensive trial and error solutions laid before you, there’s one really wild solution out there.

Here’s the solution by a user, if you’re brave enough:

“I once had a similar thing happening for a lamp, and it turned out that turning the wall plug by 180° (thus switching phase and neutral) ‘fixed’ it.”

Yes, simply rotating the plug can also fix your flickering LED bulb sometimes. Science IS magic.

FAQ

Why Does My Dimmable LED Flash?

Usually the cause of a dimmable LED flashing is the result of an incompatible dimmer switch. Make sure you’re using LED light bulbs that can be dimmed and that you’re using LED dimmers designed for LED lights.

Do LED Bulbs Flicker Before They Burn Out?

Usually, no – LED bulbs will get dimmer as they burn out, but lights flickering doesn’t normally mean that they need to be replaced. If your LED light bulbs have been getting dimmer and then start flickering, consider replacing them.

Will Taking The Bulb Out From Fixture And Resetting The Fuse Box Fix Flickering?

In most cases, removing a bulb and resetting the fuse box won’t fix it. The only time this will work is if the circuit has already flipped, and the reason the bulb is flickering is due to residual power.

Can Different Types Of Light Fixtures Cause Flickering?

LED bulbs generally run a lot cooler than older types of light bulb, but this can cause them to flicker if they do overheat. Certain older types of light fixtures, particularly recessed lighting, are more prone to overheating if not properly installed or protected.

Final Words

Now that you know a few possibilities of why your LED fixtures might be flickering.

It could just be that you’ve not used the correct bulb – but my bulb picker tool can help.

It will also help you make sure you choose the right shape and size of bulb for your fixture, too.

Looking for an LED bulb but not sure what type you need?

Check out my free bulb picker and select the right bulb within few clicks.

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