Last Updated on June 4, 2023 by Dave Farquhar
An outlet sparking when plugging in is scary when it happens, so I don’t blame you for asking. Is it normal to see a spark when you plug something in?
A spark, also called an arc, happens when electricity jumps from one surface to another, and is usually too small to even notice. If you routinely see a big spark when plugging something in, you need to do something about it, but the cost is frequently very low or even free.
Table of contents
- Outlet sparks when plugging in
- One simple fix if an outlet sparks when plugging in
- Is it normal for a plug to get hot?
- What causes an electrical outlet to burn?
- Choosing a replacement outlet
- Safety precautions
- Cleaning up sloppy wiring and replacing the outlet
- Finishing up the outlet replacement
- Do electrical outlets go bad?
- Is it normal to see a spark when you plug something in?
Outlet sparks when plugging in
Electricity is lazy. It will always take the shortest, quickest path it can find to ground. Literally, the ground outside, where there’s effectively an infinite number of electrons. But electricity really, really wants to get to ground. When you make metal to metal contact, it jumps from the outlet to the plug. If it’s not clean metal to metal contact, you see a spark. You may even hear a bit of a pop.
The spark and the pop is called an arc. Arcing means electricity isn’t getting good metal-to-metal contact. Occasional arcing isn’t necessarily a problem, but if you notice it a lot, it’s probably bad enough to be a problem, or to cause a problem. That spark will also attract dust from the air and deposit that dust on the plug or inside the contact in the outlet. That blocks some metal-to-metal connection, which leads to more arcs, which captures more dust and deposits it in the flow, and on and on.
One simple fix if an outlet sparks when plugging in
One simple thing you can do if an outlet sparks when plugging in is to check for an on/off switch. If you plug something in while it’s switched on, it immediately wants electricity, even before the plug and outlet made a good connection. Switching off the switch and only powering it on after it’s plugged in frequently solves this problem. Not always, mind you, but frequently enough to be worth trying.
If that’s not enough to solve your problem, there’s probably something else going on. Especially if your plug gets hot while it’s plugged in.
Is it normal for a plug to get hot?
It’s not normal for a plug to get hot. Heat when electrical current is flowing means there’s resistance going on. You won’t eliminate resistance but you want to reduce it. This reduces the risk of electrical fire, and also reduces the risk of your electrical appliance malfunctioning. If your plug is getting hot, it may mean your appliance isn’t getting enough current.
If your plug gets hot, it’s eventually going to cause the electrical outlet to burn. That’s bad. But there are two main causes for that, and they aren’t especially expensive or difficult to fix.
What causes an electrical outlet to burn?
When I used to buy a house to fix up, I almost always found one burned electrical outlet somewhere. A burned electrical outlet was frequently one of the reasons a house fell into my price range. Other potential buyers saw the burn mark and it scared them off.
I’ll let you in on one of my secrets though. You’ll need to replace the outlet if it burns, because those burn marks look bad and they may indicate other damage. But it’s usually just a sign of sloppy wiring right at the outlet. It’s not usually an indicator of bigger problems. The replacement electrical outlet will cost you about $2 at the nearest hardware store or home center, and it’ll take you 30 minutes to replace it and clean up the wiring.
Most of the time when I see an electrical outlet that burned, it was poor wiring or a worn-out outlet. Use of a high-demand appliance like a space heater can also cause an electrical outlet to burn. If you’re using a space heater and it’s giving you problems, don’t run it at full power. Most space heaters I’ve seen can run at 600, 900, or 1,500 watts. The 1,500-watt setting is almost always problematic, and 900 watts almost always does a good enough job.
If you have an electric space heater, run it at 900 watts.
Choosing a replacement outlet
Buy an outlet that matches the one you have. If it’s a two-prong outlet, get a two-prong outlet. Don’t replace a two-prong outlet with a three-prong and leave it ungrounded or create a bootleg ground. That’s dangerous. If it’s a three-prong outlet, look for whether it’s 15 amp or 20 amp. If one of the slots is a T shape, it’s 20 amp. Don’t replace a 15 amp outlet with a 20 amp outlet.
Also, I don’t recommend you buy the 75-cent outlet. The 75-center is OK for seldom-used outlets. But it’s not going to hold up well under vacuum cleaner loads. If you want to be safe, buy the commercial grade outlets that cost around $2.50 each. I use commercial grade outlets in the high traffic areas. That way I know it will last a while, and I won’t be replacing it again in a year or two. I’ve replaced enough outlets that I’m pretty good at it now, but it’s not something I enjoy. If you’re new to wiring outlets or you don’t like wiring them either, you might consider the Leviton Decora Edge outlet, which costs around $3.50 and has push-in connectors with levers to secure the wires. You can wire one in about one minute.
With a properly wired, quality high-grade outlet, sparks, arcing, burn marks and plugs getting hot will all be history.
If the cover plate is broken, buy a new cover plate too. Unbreakable cover plates aren’t actually impossible to break, but they are much less brittle than traditional cover plates. I try to buy oversized unbreakable cover plates when I can. That way if there are any dings or bad paint right around the outlet, it covers it.
If your outlet hasn’t burned and isn’t loose but gives you problems, you may just need to rewire it. Follow the instructions below with your existing outlet if that’s the case. Cleaning up the wiring costs nothing but your time.
Simply shut off the power to the outlet at the electrical panel. Double check the outlet for power to be certain it’s dead. Remove the cover plate, then remove the two screws holding the outlet in place. Pull the outlet out of the wall and look at the screws holding the wires in. If the wire isn’t looped around the screws, or you see insulation under the wires, or worse yet, both, you found your problem.
Cleaning up sloppy wiring and replacing the outlet
Remove the wiring from the screws. You’ll probably want to do one wire at a time, moving from the old outlet to the new one. The white wire goes to the white metal. The black wire goes to the gold metal. White to white. Black to gold. If the outlet has a ground, the green or bare wire goes to the green screw on the outlet. Green means ground. If you’ve never done this before, take pictures with your phone so you’ll have them for reference.
Using a pair of needle-nose pliers, bend the wire into a loop. You want it to fit pretty tightly up against the threads of the screw, so it makes good metal-to-metal contact. Also strip back just enough insulation so that the head of the screw makes full contact with the wire. You want insulation after the screw, but not under the screw. Again, good metal-to-metal contact. After you loop the wire around the screw, pinch it down with the pliers so it wraps around the screw.
Not everyone’s dad knew this trick, so not everyone knows it now. But this trick not only makes the outlets work better, it actually makes them easier to install, which is nice.
You may have one pair of wires or two. Take your time, make sure you have good metal to metal contact, then wrap the whole outlet with some black electrical tape. This will keep the screws from accidentally making contact with a metal electrical box and shorting out. It also gives some protection against oxidation, which will make the outlet last longer.
If this sounds difficult, here’s an easier option. A Leviton Decora Edge outlet has push-in connectors with levers to secure the wires. They cost around $3.50, but the ease of wiring may be worth it to you.
Finishing up the outlet replacement
With all that done, fold the wires neatly back into the electrical box, position the outlet, and screw the new outlet into the wall. If the box or the outlet are loose, here’s how to fix loose electrical outlets. It’s not hard. You can do that too. Then replace the cover plate.
What if the wiring looks ok but you still have burn marks? The outlet went bad. That happens. That’s a good indicator you need to step up to a higher grade outlet.
Do electrical outlets go bad?
Yes, electrical outlets do go bad eventually. The force of plugging and unplugging eventually takes its toll and wears out the contacts inside the outlet. They get looser and looser with time, making worse and worse contact. In extreme cases it can cause burn marks on the outlet. The biggest tell-tale sign, though, is that it’s just too easy to plug stuff in.
A rarely used outlet won’t go bad just sitting there. I’ve seen ancient outlets that probably date back to the Eisenhower era that still work just fine and give a nice, tight connection. The outlet behind the TV, and the outlet behind the dressers in bedrooms will last a long time, because the only time those ever get touched is when someone buys a new TV or a new lamp. That’s probably once every several years. The outlets in high-traffic areas where people plug in vacuum cleaners, charge their phones, and plug in anything else that they want to be able to move quickly see a lot of action. So do the outlets in bedrooms where people charge their phones and laptops.
A good quality outlet in a high traffic area will wear out in 20 years or so. A cheap outlet will wear out sooner than that.
Is it normal to see a spark when you plug something in?
So, is it normal to see a spark when you plug something in? Not if it happens a lot. And it can lead to other problems, like plugs getting hot, burn marks on the outlet, and possibly even the outlet going bad before its time. Fortunately, this is a problem you can fix yourself pretty easily. If you’ve never done this before and you’re uncomfortable, enlist the help of a handy friend. Chances are you know someone who has.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.