What Causes Lights To Flicker? The Most Common Reasons Explained

By Kenvin F / August 7, 2016


We've all been sitting in a room at some point in our lives minding our own business, to then suddenly realize the light is flickering. It's the kind of thing that stops you doing what you're doing and forces you to investigate, as not many things grab our attention more than what is essentially a flashing light.


Here we want to provide you a quick list of the reasons this overly distracting issue comes about. You may have never been interested to know what causes lights to flicker in the past, but there is always that one that bugs you so much, you can't help but find out what's causing it. We hope one of these common cases helps to explain yours.

Minor Flickers Are Inevitable

Flickers that are faint and less easy to notice, occurring periodically throughout the day can't be stopped completely. They are brought about by the varying electrical units around your home or building that draw power from the circuitry system.

The most demanding units in your home, (washing and drying machines, refrigerators, and freezers, etc.) should be drawing electricity from their own circuits. But their usage will still cause minor disturbances in the flow of your main supply wires. The vast majority of the this will be what causes lights to flicker slightly in other rooms.

The better a circuit layout is designed, the harder this low-level flickering will be to notice, but it will always be there to some degree.

Causes For Stronger Flickers That Happen At Random

If the flicker you notice is more obvious but seems to happen more randomly, the most common causes can be appliances drawing large bursts of the electrical load from the circuit. For example, someone in the house might have just turned on an appliance that requires more current on startup; this may cause a sharp flicker.

If power is drawn from the circuit very quickly, for example, someone plugging in a device that uses a large high voltage electrical motor or pump, this could also cause a brief flicker.

Electrical loads at a neighbor's house can impact yours, as residential housing are sometimes built with shared circuitry. The same can, of course, apply to office buildings, with different floors sharing the same circuitry. So the loads used by neighbors or people in other sections of your building will be impacting your electrical supply.

Sometimes the engine work around your home is the cause Lights To Flicker.

What Causes Lights To Flicker

These make up the majority of the most common causes for less frequent flickers and unfortunately nothing can be done to prevent them. Circuits will always be weakened by increasing loads, and a weakening electrical supply is always going to cause a change to the level of light provided by the bulb. Thankfully in most people's cases these varying disruptions will only be obvious now and then, and hardly noticeable the rest of the time.

Flickers That Can Represent Serious Problems

If the flicker you notice is becoming more frequent, while no clear changes to your electrical supply usage have occurred, this can indicate that more serious problems are developing. Electrical circuits run smoothly when all connections are strong. When a connection becomes loose, resistance in the flow of the circuit develops.

Resistance means a strained electrical supply. It can also mean there is resistance and heat build up at a certain loose point in the circuit. If left alone, this error can lead to sparking, or even inflammation if it comes into contact with certain materials. Loose connections over time can cause real damage to the entire electrical system, which will need repair by an electrical technician.

A constant resistance in the circuit will not only cause your bulbs to frequently flicker, it can also cause your light switches to fail. It is very important to have trained experts work on failed switches that require dismantling, as they are actual contact point to the circuit.

Investigating That You Can Do

If the flicker is only minor and random like described in the first sections of this article, there is little need to investigate further as not much can be done. But if you notice the flicker growing in frequency or clarity, here is a basic step that you can take to try to identify the cause of the issue.

You can try isolating a certain appliance that might be causing the flicker. To do this you'll need to firstly locate your breaker panel. Plug in one appliance at a time, and for each one goes over to the breaker panel right after inserting them into the power supply.

If the breaker seems to buzz more than usual or crackle, it means the appliance plugged in is impacting the circuit flow and is very likely the causing a flicker.

Once you have an understanding of the exact instruments that are causing the flicker, you can then decide if improvements need to be made to your circuitry. A trained electrician will be able to more accurately measure the voltage capacities of your circuit and the level of voltage required when certain devices are turned on.

If you think you'd benefit from seeing an expert demonstrate a variety of ways to explore the situation, you might find this video on how to fix common electrical problems useful.

Do not be tempted to make changes to your breakers or electrical circuitry if you have had no prior training in electrical engineering. This work should be done only by an adequately trained and insured electrician. It can very tempting


We very much hope this quick explanation of what causes lights to flicker has helped provide you an idea of what to look out for. While infrequent minor flickers can be ignored, frequent flickers are worth paying more attention to, so don't take the risk if you're noticing it occur more often.

Please let us know if you've found any more interesting reasons for you lights to flicker, or if you think there are any basic points we may have missed.

If you think this article would be of interest to anyone who might benefit from this information we hope you'll send them a share!​

About the author

Kenvin F

Greetings and welcome to our Home Improvement site! There are few things as rewarding and fun as working on your own home. The fact that you're here tells me you want to learn and get involved with your home too. I'm here to help you every step of the way. You can do this! Join me, won't you?

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