Why Does My Light Switch Get Hot? (Find Out Now!)

Brigid Levi
by Brigid Levi

If your light switch is hot to the touch, it could be related to a few different reasons. But the biggest thing to note is a hot light switch is a fire waiting to happen. As soon as you notice the temperature is warmer than warm, call a professional right away.

A light switch gets hot if the switch is overloaded. Different switches have different power ratings, and you shouldn’t have more fixtures on the switch than it can handle. When a switch starts to wear out and fail, it will get hot to the touch. Faulty or improperly installed wires spark and generate heat which also causes the switch to get hot.

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When a Light Switch Feels Warm

Before we discuss the reasons a light switch gets hot, let’s talk about switches that are warm to the touch. This is actually perfectly normal, especially for dimmer switches that are turned on.

This warmth comes from an electrical component called the triac. For alternating currents, this component is called the triode. As the current passes through the light fixture, the triac or triode fluctuates the amount of electricity.

You might feel a small amount of warmth if the dimmer is tied to a 100-watt load. The heat becomes more noticeable once the load reaches over 300 watts.

When a Light Switch Feels Hot

If warm is normal, hot is definitely not. If your light switch feels hot to the touch, there is a big problem that could lead to an electrical fire.

A light switch feels hot if…

  • It’s overloaded
  • It’s failing
  • The wires are faulty or weren’t installed correctly

Overloaded Light Switch

Similar to outlets, light switches have a limited amount of power they can handle. Different switches have different power ratings. If a switch is overloaded, there is a serious risk of fire. It should immediately be replaced with a switch that has the proper amps to support a fixture.

Most residential light switches are rated to carry 15 amps. Industrial switches are usually rated at 20 amps. Your breaker panel will be able to tell you how many amps the light switch can carry.

A further solution to this problem is to replace the faceplate. Plastic tends to hold more heat, while metal dissipates it. Replacing a plastic cover with a metal one may also cut down on the heat you feel.

Failing Light Switch

After much use, a light switch can start to wear out. They should last a very long time, but they do need to be replaced at some point.

When they wear out, the electrical contacts produce small sparks every time the light is turned on or off. The electricity begins to flow more freely over time because the contacts aren’t meeting correctly. As the sparks fly, they heat the switch, making it feel hot.

It should be pretty obvious that freely flying sparks are a major fire hazard.

Faulty or Improper Wire Installation

It doesn’t matter if the wiring was professionally installed. As it ages, wiring can become broken or loose. Light switches also retain heat over long periods of time. This can cause cracks in the wire’s insulation, which can, in turn, cause short circuits, arc faults, or fires.

When a wire loses its integrity, the results are similar to a failing light switch. Any bad connections will spark and generate heat, and you’ll feel it on the light switch itself.

Additionally, bad wiring can block a current’s flow which also produces heat. The best way to fix faulty wiring is to have it replaced by a licensed professional.

Hot Dimmer Switches

We know a warm dimmer switch is normal. But a hot one is not. If you have an older dimmer switch, you may notice it gets hot when you dim the lights. A modern dimmer switch on the other hand may get hot when brightening the light.

This is a result of an overloaded or unevenly balanced current. The switch’s rating is not sufficient enough to carry the wattage of the bulb in the fixture. You can either change out the switch for one with a higher amp rating or use a bulb with a lower wattage.

Other Switch Issues That Require a Professional

Sometimes, there are DIY fixes to electrical issues. But because of the danger involved, it might be best to call an electrician. In addition to a light switch feeling hot, you should call a professional for the following things:

  • Your home has an old fuse system
  • A light switch doesn’t have a solid connection when in the off or on position
  • Your lights dim when the HVAC turns on or when using a major appliance (like a vacuum)
  • One of the two electrical sockets in an outlet is dead

Related Questions

We’ve discussed a good many reasons why your light switch feels hot and what you can do to fix it. Perhaps you still have more questions. Below are some other things people wondered about the functions of a light switch.

Why does my light switch spark?

Most likely, this is occurring because the switch is worn out. Above, we talked about how poor connections can cause sparks. These sparks can sometimes appear on the other side of the faceplate where you can see them.

Similarly, if you operate the light switch too slowly, the connectors have a gap just far enough for an arc to occur. Meaning, the electricity literally arcs from one connection to the other in mid-air. This may also cause a visible spark.

How hot should a light switch get?

The general rule is if you can’t touch the light switch for more than a few seconds, it’s too hot. Some switches are built to withstand temperatures up to 195 degrees Fahrenheit. However, the average dimmer switch is built to withstand temperatures around 140 degrees Fahrenheit.

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Whether it’s a problem with the wiring or an overloaded switch, a hot light switch is no joke. Have a professional take a look ASAP to avoid further damage to the switch or an electrical fire.

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Brigid Levi
Brigid Levi

Brigid Levi is a wife, mother, and freelance writer who enjoys a good DIY project and creating beautiful spaces within her home. From cleaning and organization hacks to home decor ideas, she loves helping people in their quest to turn a house into a home. Her hobbies include pretending to be Joanna Gaines while updating her home with her husband and performing in local theater productions.

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