Why and when your LEDs glow after switching off?

Susan Fernandez February 02 2022

Your house is dark. You flip the switch on your lights, but nothing happens. Why are you finding it difficult to see in the dark? Does something have to be done before you can turn on the lights? The answer is no, but there is a trick behind this little conundrum - your light bulb glows when switched off because of how it was made!

Why does it happen?

Light bulbs are full of an element called tungsten. Tungsten has one very unique property - it glows when an electric current runs through it. This process is called incandescence and allows us to see even in the darkest areas.

If you were to open a light bulb, you would see that it consists of a glass tube surrounded by glass and filled with argon gas. In the middle of this tube is a thin coiled metal filament or wire made from nickel-chromium alloy. An electrical charge sent through the coil causes the tungsten to heat up and glow brightly. This process creates visible light.

The problem is, when there isn't any electricity going to the bulb, the only thing putting energy into it is its own heat - which makes it so hot that no one can touch it! If you try to lit your home with these kinds of bulbs, they will quickly overheat and break, leaving scorch marks on your floor's ceilings!  It's just not worth the risk!

The solution involves creating a light bulb that automatically breaks this cycle. There are two types of light bulbs to accomplish this - fluorescent and LED. These special kinds of bulbs use only electricity to create light, so they can be safely left on for long periods of time without hurting anything.  

Is it normal?

Glowing after being switched off is not 100% exclusive to all light bulbs. LED bulbs are the only kind that never needs time to cool down before they can be switched on. Fluorescent, like what's most commonly used in homes, require a few minutes of cooling time before they can be turned back on without getting too hot and breaking.

Glowing after switching off is simply how these kinds of bulbs were designed! They don't hurt anything by glowing after being turned off, so there is no reason for them not to do this! It's just something you have to deal with if you want your home lights on for more than an hour.

Do all bulbs glow after switching off?

What about other types of bulbs, do they also glow or not? This depends on what kind of bulbs these are. Compact fluorescent bulbs and LED lights do not glow after switching off, but all other types will continue to emit light when they are powered down. This occurs when the filament in a bulb has been heated to high temperatures.

In incandescent light bulbs, it is generally not a problem because the gas inside the bulb protects the filament from burning out quickly, but in halogen lamps, metal halide lamps, and mercury vapor lamps, there simply isn't enough atmosphere inside the bulb for protection. These special kinds of bulbs must be handled differently because they can actually burn or shatter when you try to turn them off!

Examples: Incandescent, halogen, metal-halide, and mercury vapor.

What about LED strips? Do they also glow? Yes, because they are built from individual lights that have been connected together, you should treat the strip just like a regular light bulb.

Does this mean I will have to live in the dark?

It is possible for some light bulbs to stay on long enough to cause damage, but this usually does not happen. Light bulbs actually do a pretty good job of turning off when they are supposed to, and can even last about 10 times longer than incandescent bulbs!

This is why more and more people are starting to use compact fluorescent, LED, or other new light bulbs - it's safer!  And while some older types of bulbs continue to emit some light after being switched off, there still isn't a way around having your room go completely dark if that's what you want... until now.

Inventors all over the world have been dreaming up a way for light bulbs to be turned on and off again without stopping the flow of electricity. One such invention, called Smart LED, is able to send electricity back into the bulb after it has been turned off! This allows you to switch your lights on and off, without ever having to worry about wasting energy or causing heat damage.  

If you're looking for ways to cut down on electricity use or simply want an easier way to turn your lights on, ask your electric company if they offer LED bulbs in their supply catalogs!

What are other reasons for your bulb glowing?

  • High resistance:

Sometimes the filament in a bulb might not like the amount of electricity that is passing through it. If this happens, sometimes electrons can build upon one part of the filament and make it too hot to touch. Other times, this means your bulb will work fine but burn out more quickly.

  • Old wiring:

Light bulbs that are connected to old wiring might start glowing after they are turned off because there isn't any insulation inside the wires! You should always look at the manual for your light bulb before you apply power; if you're using anything older than about 1930, chances are good that your lights will glow after being switched off.

  • Bad connection:

If electric current does not flow out easily from within a bulb, some parts of this electrical path might become very hot, even after the light switch is turned off. This is why it's important to use light bulbs that are rated for your specific voltage - otherwise, they will start to glow!

  • Heat damage:

If an incandescent bulb has been on for less than a minute and you turn it off, this means there wasn't enough time for the filament to cool down completely before being exposed to oxygen again. When filament temperatures climb above 1200 degrees Celsius, this can cause permanent damage and reduce the lifespan of your bulb.

  • Faulty fixture:

Your house does not need precise 110 volts AC (alternating current) in order for lights to work. If your home really only receives 100-105 volts, sometimes those extra electrons can cause your lights to glow even if they are turned off.

  • Vaporizing inside the bulb:

Only some types of light bulbs actually contain any of these materials, but you might be surprised to learn that fluorescent lights are filled with trace amounts of mercury vapor! This is why it's important not to break fluorescents in your home - otherwise, this metallic element will escape into the air and cause harm to your health.

  • Overloaded sockets:

If too many appliances are plugged into one socket, or if the wrong size fuse was accidentally installed when your house wiring was updated... sometimes parts of an electric circuit can get overloaded! If this happens, glowing bulbs are only a matter of time. To prevent overloads like this, make sure you never try to use more than 12 regular-sized light bulbs on a 15 amp circuit. It is also important that you use the right size fuse when updating your house wiring.

Should you change the LED bulb to another one?

If you don`t want your bulb to glow, you should change it to another one. It`s better than leaving it as it is, or just try to replace the fixture with a new one - that way you would additionally save energy and wouldn't have to look for solutions. If problems with your LED bulb can not be solved, contact an electrician who will solve them for you!

However, there are other types of light bulbs that don't glow after being turned off. For example, CFL (compact fluorescent lamps) do not glow either after being turned off so using these instead of regular light bulbs will help you prevent this problem. Today there are many different types of light bulbs available on the market so choose wisely what kind fits your needs best!

Replacing your LED bulb with incandescent won't do the job since they are really different types of lamps. For example, incandescent lamps glow because of the high temperature, but LED bulbs are inactive when they are hot. Also, incandescent lamps give light by glowing, LED bulbs give it by emitting light of a certain wavelength. In short, you can get rid of this problem by replacing your bulb with another one that is made for the same type of socket as this LED bulb (don't forget to read its manual!).

Before buying any new type of lamp - make sure you're familiar with all characteristics and regulations about it! Ask an electrician if needed, but try to find out everything yourself before making any decisions. Make sure you do not regret it afterward because otherwise money will be lost and you`ll still have to solve the problem somehow! Also, don't forget that light bulbs are not eternal.

Even though they might last long enough for some people during one year, most LED bulbs last up to around 15000 hours! They are made for saving your money and energy so you still have to change them if needed.

How can you check the wiring in your house?

In case you don`t want to replace the LED bulbs and everything seems to be OK, you might think about examining the wiring in your house.

You can use an electrical tester which you can purchase in your nearest store. It will detect any problems with the wiring, so you won`t have to call an electrician for help. However, if there are no electronic testers available, you should have access to a voltage meter. If it shows up that one of your wires is disconnected or damaged somewhere - make sure you fix this problem immediately! Otherwise, it might cause injuries and maybe even fires.

Do not touch anything when checking the wiring! Electricity is very dangerous and can lead to injury and death. Follow all instructions and stay safe.

If the lights do not glow even though everything seems to be OK, try replacing them with other LED bulbs because they could be faulty. Replacing one bulb with another is the easiest way to solve this problem without breaking a sweat or spending too much money.

As it was mentioned before, LED bulbs are fairly new on the market and there are still some problems that can occur. If you want to be 100% sure your house wiring is OK - contact an electrician for help! They know how to deal with these situations so they will not have any issues helping you out.

If none of these solutions seem feasible, try looking for other options besides LED lamps. Remember that light bulbs which don't glow usually cost more than regular models but having great lighting in your home might be worth spending some additional funds on that. You could also visit different shops where they sell household appliances and ask their employees for advice. Also, if the problem continues after all of these remedies - you might consider buying new fixtures because they can be faulty as well!

If you are looking for some additional pieces of information on how to solve this kind of problem yourself - go online and look for some detailed instructions. Or maybe there are some electricians which offer consulting services by phone? Look around online because LED light bulbs are becoming more popular on the market with each passing day. You should find what you need without any issues!


Although the LED bulbs are still new on our market, there are some issues that can occur even with them. If you want to save your time and money - try to find this problem by yourself before contacting an electrician or trying any other way of solving it. You don't have to give up on LED light bulbs because they save energy and money in the long run!