Why are my lights flickering? Common causes and how to fix them

Flickering lights can be quite annoying. They disrupt the ambiance of your home, create distractions while relaxing or working, and can even strain your eyes.

Naturally, this makes you wonder, "Why are my lights flickering?" The reasons might not be what you expect. Some are common, and you can immediately fix them, while others are not.

Keep reading to understand the cause of flickering lights and learn how to identify and fix them.

Start with the basics — is it the bulb?

If your light flickers, it could be because of the bulb. Make sure it’s screwed in tightly. If that doesn’t resolve the issue, replace it with a high-quality, compatible one. If the flickering stops with a new bulb, the previous bulb is likely the culprit. 

However, if the flickering continues, the issue lies elsewhere. For instance, modern LED bulbs don’t work well with traditional dimmer switches, leading to inconsistent voltage delivery that causes flickering. Circuit overloads, aging or damaged wiring, or an overloaded grid can also contribute to flickering lights.

So, why are the lights in my house flickering? Let's break down some of the possibilities.

Look at the fixture and plug connection

If replacing the bulb doesn’t solve the flickering problem, the issue could lie with the lamp fixture, plug connection, or wall outlet. 

Sometimes, the bulb may not be seated correctly in the socket, creating an intermittent electrical connection that leads to flickering. Even if the bulb appears securely in place, the contacts within the socket could be loose, corroded, or damaged, causing an unstable power flow. To test this, swap the bulb into a different lamp. If the flickering stops in the new lamp, it’s likely that the issue lies with the fixture.

Similarly, a loose or worn plug connection can be to blame. If the plug’s prongs are visibly bent, loose, or damaged, the internal wiring or connection points are likely compromised, causing the lamp's power supply to be unsteady. To fix this, cut off the damaged plug, purchase a new plug from a hardware store or online, and attach it.

In some cases, the wall outlet could be the problem. Loose wiring or worn-out connections inside the outlet can trigger flickering when you plug in the lamp. A quick test is to plug the light into a different outlet. If the flickering stops, the problem is likely with the original outlet. In this case, you need to have the outlet replaced or repaired.

Consider voltage fluctuations

When large appliances like your HVAC system or microwaves pull power from the same circuit as your lights, they can cause temporary voltage dips or spikes that disrupt the existing stable power supply, leading to light flickering.

Use a voltmeter to measure the outlet voltage and check if it falls within the normal range of 115V to 125V. If the voltage is inconsistent or remains outside the normal range for a prolonged period, it could be a sign of an overloaded or underpowered circuit, faulty wiring, or problems with your electrical panel. Contact a licensed electrician, as they will be able to identify the root cause of the voltage fluctuations and help you resolve it safely.

Dimmer switch or compatibility problems

Still wondering, “Why are my LED lights flickering?” Dimmer switch compatibility might just be the reason your light keeps flickering, especially when using modern LED bulbs. Traditional dimmer switches control the light intensity by adjusting the voltage passing through to the bulb. Incandescent bulbs use a filament that can handle various voltages and works well with traditional dimmer switches.

On the other hand, LEDs are more energy-efficient and use a driver to convert the power they receive. These drivers are sensitive to fluctuations and need steady voltage delivered to the bulbs. Hence, when traditional dimmers are used with LEDs, the voltage becomes unstable, leading to flickering or buzzing sounds as the dimmer struggles to regulate the current. 

The simplest solution is to upgrade to a dimmer switch compatible with LED bulbs or to replace your current bulbs with dimmable LED ones that work with your existing dimmer.

Circuit overloads and home electrical issues

Every electrical circuit in your home has a limited capacity. When too many devices or appliances draw power from the same circuit, there may not be enough power for each device to operate correctly. As a result, lights on the overloaded circuit can begin to flicker or dim, especially during peak usage.

The solution is to spread your appliances across multiple circuits. Plug high-draw appliances like a vacuum cleaner, space heater, or microwave into outlets connected to different breakers to distribute the load evenly. If that’s impossible or doesn’t solve the issue, hire a licensed electrician to assess your current setup and upgrade your home’s electrical system.

Aging or damaged wiring

When wires become loose, frayed, or corroded due to age, wear, and tear, they create points of high resistance or intermittent contact within the electrical circuit. This unstable connection disrupts the steady flow of electricity, causing the voltage to fluctuate and resulting in flickering lights.

Unfortunately, damaged wiring doesn’t stop at flickering. When the connection becomes intermittent enough, or when there’s a small physical gap between the damaged wires, electricity can jump across that gap. This is called arcing. It can produce sparks behind walls or junction boxes, significantly increasing the risk of an electrical fire.

That’s why you should never ignore any signs of faulty or failing wiring. If you notice flickering or dimming lights across multiple rooms or throughout your house, especially when no large appliances are running, it may indicate a broader problem within your home’s electrical system. Other red flags include burning smells or buzzing or crackling sounds. Call a licensed electrician as soon as you notice these signs.

Utility or neighborhood-wide issues

Sometimes, the light flickering problem isn’t within your home’s wiring, fixtures, or circuits but in the power supply coming from the grid. Voltage fluctuations from the utility provider, issues with shared transformers, or even damage to nearby power lines can all affect the consistency of electricity entering your home. In turn, it can cause your lights to flicker or dim.

A strong clue that the issue is external is if your neighbor’s lights are flickering too, especially around the same time as yours. This points to a supply-side issue, like an overloaded grid. The best course of action is to report the issue to your utility provider. They can inspect the distribution lines, transformers, and other equipment servicing your area to determine and fix the problem.

Is light flickering dangerous?

Occasional light flickering isn’t always something to worry about. However, consistent, worsening, or sudden flickering can signal that something more serious is happening. It points to underlying electrical issues that could pose real safety risks.

If you notice any of these signs alongside flickering lights, turn off power to the affected area immediately and call a licensed electrician to identify the cause of the problems and resolve them.

• Flickering accompanied by burning smells.
• Repeated flickering in multiple rooms.
• Circuit breakers tripping frequently.
• Buzzing noises or visible sparks.
• Outlets and switches that are warm or hot to the touch.

When to call a professional

If you’ve already ruled out simple causes like a loose bulb, a faulty plug, or an incompatible dimmer switch, and the flickering continues, it’s time to call a professional. Persistent flickering is often a sign of a deeper electrical issue that requires professional attention. 

Don’t attempt DIY fixes for wiring, voltage irregularities, or anything involving your breaker panel. These systems are dangerous to work with and may pose serious risks if mishandled. A licensed electrician has the tools and experience to safely inspect your home’s electrical system, identify the root cause of the flickering, and perform necessary repairs or upgrades.