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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 offIt’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.

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.

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

Why Are All My LED Lights Flickering In The House?

graphics why my LED lights flicker

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.

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.

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