Why Do My LED Lights Flicker And How To Stop 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, so here’s a quick rundown of the reasons why your LED might be malfunctioning.

It’s useful to know that LED functions as a computer. It has a binary on and off status and no persistence like traditional light bulbs.

So if the on/off cycle, powered by mains alternating current (AC), is not functioning well, then the human eye sees the LED rapidly turn on and off, which we call flickering.

There are several reasons why the bulb is behaving this way, but mainly:

The low frequency of less than 50 Hz makes the LED bulb flicker. Your LED bulb might be flickering due to loose or incorrect wiring, incompatible dimmer switches, or bulb components such as a defective LED driver.

LED Lights Flicker Without Dimmer

To cut to the chase, three points of fault usually make lights flicker. The fault could lie in the LED bulb, in the wiring, or in the current regulation.

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 in your LED light bulbs.

The bad LED driver components that could not withstand the sustained heat from the other internal components. Suppose it’s your hobby to crack open electrical components to see what went wrong. In that case, you should be looking for a swollen or bulgy capacitor.

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

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.

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

For example, having incandescent bulbs connected to the same circuit as LED lighting will make LED flicker. The reason is that traditional bulb uses 100% of needed energy, most likely 60W, leaving the rest of the supply for appliances such as LED lamps.

Having a couple of incandescent bulbs will quickly draw all the power leaving none to nothing for your LEDs, which will make them flicker due to the lack of power.

What Causes LED Flickering on Dimmer Switches?

turning the dimmer switch

Since you now know that LED tech functions 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.

Incompatible dimmer switches wired to a newer LED light fixture or bulb will produce a flickering problem which is uneven flicker frequency (on/off at irregular intervals), indicating interference.

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 the 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

Why Do LEDs Flicker Even When Lights Are Off?

turned off

It’s no wonder that ‘magic’ in the olden days was just science tricks a common person didn’t know about.

Because here in my guide, things get a little stranger, and thus the answer is a little bit more technical about light bulbs.

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.

One of the things that can be common in all such flickering LED lamps despite being switched off is a fancy switch.

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.

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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 incorrect circuitry, the switch may not utilize the neutral wire. The LED is on the negative wire, which leads to capacitive coupling leading to residual power in the capacitor.

With this stray capacitance and current leakage, enough voltage can build up in circuits, making 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 capacitance and 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.

Why Are All My LED Lights Flickering In The House?

lights flickering in the house

When not all the LED lights in your home are flickering, but just some of them, then at least you can rule out a problem with specific light bulbs or connections.

If your whole house has dimmer switches installed, then it might be the issues I’ve mentioned above, but otherwise, there are two main culprits.

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

This can usually be attributed to a high-powered or large appliance on your home circuit, as I mentioned above – such as running an electric fan or charging your electric car.

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?

can flickering light cause fire?

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.

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.

It’s definitely not to be taken lightly.

Some other ailments that can arise due to flickering LEDs are blown fuses, tripped circuit breakers, or even burning smell from an appliance due to overload.

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

Now, that was about visible flickering.

Sometimes, bulb flicker cannot be detected by the human eye but is still registered by your brain, affecting it negatively.

A simple way to locate flickering bulbs not seen by your own eye is to point your phone’s camera to 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 not fixing it can be a cause of an epileptic seizure in someone with the illness or accidents resulting from a lack of concentration.

How To Stop and Prevent Flickering in the Future?how to prevent flickering

Let’s walk through the troubleshooting process. The easiest elimination is the bulb.

So before anything, give the LED bulb a little twist, making sure it’s not simply a loose bulb giving you all this trouble.

And while you’re at it, wipe the inside of the bulb’s socket and any LED fixture, removing dust and ensuring a better contact.

Now, swap out the LED bulb with any other bulb, and if the new one works well, you know the fault was in the bulb.

If the bulb was fine, then check your electrical panel for loose wiring. If you’re comfortable with electrical work, then give the screws in the panel a nice twist. The screw should be snugly fit but do not over-tighten.

Now, if the bulb was 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.

The next thing that is responsible for well-functioning LEDs is a well-functioning power supply unit.

A regular one will change AC to DC current, on which LEDs run, and a better power supply will have constant current drivers installed that stabilize the current to the LED by varying voltage. This ensures constant brightness. Most modern LED bulbs have drivers already installed on the chip inside.

Moving on to the issue of incompatible new LEDs with older dimmers, the sure-fire way to prevent future flickering is to read the labels. The LED fixture box mentions which type of dimmers they will run well with.

The best practice is to look up compatibility online by putting your bulb’s model number and the existing dimmer switch.

Often, simply toggling the switch and finding the correct position will stop the flickering. However, this is not an ideal solution. A setting lower than 50% brightness usually kicks in a flicker.

New dimming switches (Amazon) eliminate this problem, or alternatively, you can purchase digital volt dimming systems, or zero-to-10V step dimmer.

Another exciting alternative on the market is a smart LED bulb. 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.

Also, recall that high-power appliances add load to the circuit and result in surge wattage. Move these to separate circuits connected directly to the wall.

If you’re feeling adventurous and to really look at things from a higher vantage point. Purchase a voltmeter to check the current running into your home/office to ensure it provides adequate voltage levels to run everyday electronics and appliances.

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

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. But if they are flickering without dimming, it is probably another issue I’ve covered above.

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 – it’s a sticking plaster on a wider issue, and the flickering will soon resume.

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.

In this instance, removing the bulb will help remove that residual power. When you reset your electrical system, it will start working as normal again. You can then get to work on identifying what caused the circuit to cut out in the first place.

Can Different Types Of Light Fixtures Cause Flickering?

LED bulbs generally run a lot cooler than older types of the lamp, 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.

If you suspect this might be a problem, get it checked immediately – any overheating light fixtures are hazardous.

Final Words

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

What kind of flickering did you face in your home/office?

How did you go about investigating the flicker?

Share your answers in the comments below.

14 thoughts on “Why Do My LED Lights Flicker And How To Stop It?”

  1. I have two led flood lights in the patio on the same circuit as my covered patio in ceiling lights. All together is not drawing much amps and wire capacities are well above required. When just the LED is working, I don’t see any issues. If I turn my patio lights as well, sometimes I see a pulsing pattern (not completely off and on). Both LED lights flickers at the exact same time and pattern and stops when I turn of the in ceiling lights. And sometimes all works well. Odd!

    Reply
    • Hi Roei,

      I have been talking about this issue in my other articles. But in a nutshell here is whats happening. The whole circuit is probably connecter in series which means that if your ceiling lights consume too much power there is not much left for your LEDs. This makes them flicker and doing all the odd stuff when ceiling lights are on. Are they incandescent by any chance?

      It would be good to get an electrician to check the load of that circuit and I suspect this would be the outcome.

      Eugen

      Reply
  2. I recently installed LED lights and they flickered. I had dimmers on the switches. I felt that may be the problem. So I went to google and pulled up this page. By the fifth paragraph, you had in bold letters, “incompatible dimmer” which made the dimmer switch my first troubleshooting step. Fixed it. Thanks.

    Reply
    • Hi Ken,

      Thanks for your kind words. Must admit, that although the most common reason, this is also the most commonly overlooked issue with dimmers.

      Eugen

      Reply
  3. Most common issue with this barring start up loads, or dirty power consuming devices is loose conductors. Have a qualified electrician check and reset all of the bus and breaker connections in your panel, and then again at the meter, especially if you have aluminum conductors

    Reply
  4. About a year ago we replaced an old ceiling fixture in our dining room. When we did we put five new LED bulbs and they all worked. In the last two months we have had three bulbs start flickering, one at a time. As this is very annoying, when a bulb started flickering, we unscrewed it so it no longer came on. As of now, there are three bulbs out with the other two just as bright as always. Is this about right for these bulbs to go bad or did we just get some bad bulbs?
    Thanks

    Reply
    • Hi Michael,

      The easiest thing to do would be test these bulbs in the different fixture. If they work fine then it is likely that there is an issue within fixture wiring.

      Eugen

      Reply
  5. Interesting issue I am seeing, have three identical porch lights on one switched circuit. Lights run a 24v surface mounted array with separate transformer. First light in the circuit start to flicker at fixed strobe interval. Other two down the circuit work just fine. Figured bad boost buck transformer. Replaced with new, no change first light flickering.
    Swapped first and second light in circuit LED array out flickering stayed with fixture location not with LED.
    Rewired whole fixture including hard wiring the LED to the DC side of the transformer. Still flashes

    If I take the whole fixture out of the circuit the remaining two work just fine.

    Reply
    • Hi Ben,

      Seems like the first of those fixtures has messed up wiring and it interferes with each other. But as you can imagine it is hard to analyze via one comment without seeing the issue.

      Eugen

      Reply
  6. Hello,

    We have a new home and noticed at night almost like clock work (little after midnight) the led can lights on the master bedroom circuit flicker on when the switch is off. The flicker is very low and last a few second. We’ve noticed it happening more frequent (or maybe have just slept through it 10 minutes or longer intervals). They all flicker – at the same time. We do not have a dimmer switch in our home. All the switches are off. Any recommendation? They run on the same circuit as our outlets and we do run a box fan at night which we turn on around 7:00 every night. Not sure if that’s relevant but we are stumped.

    Reply
    • Hi Matthew,

      In fact, the box fan can cause an issue. If your lights flicker with a turned-off switch then the circuit leaks the current into the fixtures. You need to see what exactly triggers it which would make the resolution of the issue much easier. Try to turn different appliances on the circuit and see if you can replicate the issue by yourself.

      Eugen

      Reply
  7. Hi, i appreciate the info you’ve provided and have a scenario that i didn’t see covered so thought I’d ask. In our kitchen we have 7 can lights that are LED. These were installed over 4 years ago and up until 4 months ago, no problems. These are all on a 2 pole switch(one switch on each end of the room), no dimmers. One light started flickering, but not all the time. Could be on for 6 hrs and then decide to flicker. Now, I’ve got 3 lights flickering but not on the same frequency. Turning them off for a min then back on, all is good for a min, then 1 or 2 or all 3 will flicker. Are these just going bad and need replaced or something more involved? Thanks!! Eric

    Reply
    • Hi Eric,

      Have you recently bought any new appliance that can potentially draw too much power to it? Before you buy new bulbs I would try these bulbs in another fixture (if they are not integrated) and see if bulbs work fine. This will definitely help you to direct you. If the light does the same thing in the different fixture, then most likely bulbs are doing bad, however, if they work perfectly fine then I would further investigate the switch, wiring and measure the stability of the circuit.

      Eugen

      Reply

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