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Why Do Space Heaters Melt Electrical Outlets?

Nothing triggers more panic than a burnt outlet, especially when a space heater is involved. It means the internal circuit protection has failed, and a house fire is on the table. You can’t afford to ignore this.

Space heaters can melt outlets because they require a lot of power to run. And, some electrical systems are not designed to serve power-hungry appliances. That’s why outlets melt when you turn on the space heater for an extended period.

This post dives deep into why your outlets (also known as receptacles) melt when hooked up to a space heater. It covers everything, from the anatomy of a socket to replacing an outlet yourself. 

Why Did the Space Heater Melt Your Outlet?

Generally speaking, resistance is the number one cause of heating in electrical circuits. And it is usually the result of a faulty or overloaded outlet. If either of these two things happens, the circuit breaker should cut off the power supply to all the outlets. However, these circuit protectors are not bulletproof. They can fail, causing a house fire.

A handy person can replace a faulty socket in five minutes or less. In fact, there are many videos online showing everything you need to know about this simple swap. But you can stay with me, and I’ll show you how to change sockets like a pro.

Let’s explore some of the common causes of a melted outlet.

Factor #1: Old, Worn Out Wiring 

Since the electrical system lives between walls, it is hard to notice when things wear out. Breakages allow free-flowing energy to shoot from the nearest breaking point to another exposed part of the cable. As a result, the escaping current creates an arc that heats the surrounding material. You can solve this issue by having an electrician replace any worn-out cables.

Also, old receptacles may have corroded metal pieces inside. That means the contact area is less than the recommended size, which can increase resistance considerably. If unchecked, these opposing forces cause more heat. That’s when you’ll notice burn or smoke marks on the receptacle’s face.

Fixing this is easy, replace all the outlets in the house with newer ones. It might cost a lot, especially when dealing with a big project, but it is worth the time, money, and effort.

Factor #2: Bad Contact between the Heater’s Plug and Outlet

This issue is probably the most common problem with melted outlets, and it is similar to a worn-out wire problem. The space between the plug and outlet connectors creates an arc discharge, heating the surrounding flammable material. This situation can escalate to a melted outlet or even a fire. To fix this, replace the heater’s plug and have an electrician inspect the socket.

Factor #3: Overloading an Outlet

People like to use multiple appliances at the same time. For example, you might be tempted to use the hairdryer on the same outlet as the space heater. This connection might seem convenient to the uninitiated, but it weighs heavily on the electrical system.

If the circuit breaker does not cut off the power at this point, you might notice some smoke and melt on the overloaded socket. It is even possible to find other hot electrical outlets throughout the house because they all live in the same line.

To avoid this, be sure to use the space heater in an exclusive receptacle. That gives the outlet some breathing space, making it capable of handling a heavy load. You can also use a lower power level on the space heater to reduce the amount of current it draws from the wall.

Is It Safe to Use a Melted Outlet?

The short answer is a resounding no. Any circuit with damaged outlets or devices should be de-energized to avoid further damage.

Usually, all outlets sit in the same hot and neutral line that runs throughout the house. This design simplifies the installation of sockets by having them in one circuit. But that is not always a good thing. It also means the faulty fixture will be in line with the rest of the outlets. Even if you don’t load the burnt socket, the downstream receptacles will still pass through it. That’s how thousands of houses burn down every year.

Sometimes, the outlets are not sitting in one line. That makes the set up a little bit safer than the one above, but it is still not a good reason to use a burnt socket. Replacing it costs nothing compared to dealing with a house fire.

How to Replace Old Outlets Yourself

The average DIYer can easily replace outlets in minutes. You only need one tool and a basic understanding of how an electric circuit works. Here’s everything you need to know:

The Anatomy of an Outlet

Every outlet comes with an amp rating embossed on its front face. This number should match the one in your heater’s cable. By doing this, you guarantee the setup will handle everything you throw at it.

You also need to know that outlets come in various plug prong styles. That means you should check the prongs before ordering an outlet. Any mistake here will result in more delays.

With that out of the way, it’s time to get cracking.

Step 1: Turn Off the Electricity at the Breaker Box

The first step towards fixing any electrical circuit is shutting off power at the source. Some electricians will tell you to turn off the receptacle breaker only, but it is best if you turned everything off. That is especially important if you are working in an old house. They tend to have worn out wires that pose an electrification threat.

Step 2: Remove the Faulty Electrical Outlet

Loosen the visible screws to remove the receptacle’s cover using a screwdriver. I recommend using this 11-in-1 nut driver from

Klein Tools 32500 Multi-Bit Screwdriver / Nut Driver 11-in-1 Multi Tool, 8 Industrial Strength Bits, 3 Nut Driver Sizes, Cushion Grip Handle

Step 3: Release the Wires From the Old Outlet

Once you have the burnt outlet out of the wall, open the screws that hold the wires in place. But do not try to remove the whole screw. You only want enough space to release the cables.

Step 4: Ground the New Outlet

At this point, you are ready to start the installation. Connect the bare copper wire (or green) to the grounding screw and box. That should eliminate the risk of electric shock.

Step 5: Attach Your Wires to the New Receptacle

The black wire goes to brass, and the white wire goes to silver. You will notice the outlet comes with two brass and two silver screws on both ends. It does not matter which one you choose. Just pick one and hook up the wires firmly.

Step 6: The Final Touches

Wrap the entire outlet in electrical tape to avoid polarizing. This insulation blocks the electric current from reaching the metal box. However, not all electricians think this step is necessary. 

Next, screw the outlet in the box and put the cover in place to complete the job. Then turn on the electricity for testing.

Final Thoughts

Space heaters can melt outlets for three main reasons:

  • Old, worn-out wiring
  • Bad contact between the heater’s plug and wall outlet
  • Overloading  

Using a burnt outlet is like riding a motorcycle with no brakes. Things can head south in an instance, and a house fire is a possibility. The smartest way to deal with this issue would be to replace the outlet at your earliest inconvenience. You only need to bring a new receptacle, a screwdriver, this guide and have 10 minutes to complete this straightforward DIY project.


  • Alanna Greene

    Alanna is an avid traveler who lives in Michigan. In addition to writing for Temperature Master, he also sells crafts on Etsy and takes long walks through the forests near her home.