How to Replace a Worn-Out Electrical Outlet – Part 1

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This tutorial shows how to replace a worn-out electrical outlet and explains best practices for wiring an outlet.

Electrical Outlet Hissing Noise

Electrical outlets are taken for granted until they don’t work. I started paying attention when the kids said the 1500 watt DeLonghi electric oil filled radiator space heater used to keep the bathroom extra warm wasn’t working. I checked the heater and there was no power, however I could hear a faint hissing or sizzling noise coming from the outlet. The heater plug was very loose in the outlet and the hissing noise changed as I wiggled the plug. I pulled the plug and the blades were pitted and corroded with a rough grayish film from electrical arcing and the plastic face of the outlet was melted slightly from the plug blade. A 1500 watt heater pulls 12 AMPS of current – and that’s a lot on a typical 15 or 20 AMP household circuit.

The problem was obvious: the electrical outlet was worn out from 10+ years of daily use. The metal contacts inside the outlet weren’t holding the heater plug securely and electricity was arcing across the slight gap between the loose plug and the outlet. The gap between the metal contacts causes electrical arcing – the sizzling or hissing noise – and a high resistance connection which heated the plug blades and melted the outlet face. If left alone, the outlet can get hot enough to start a fire.

I immediately replaced the electrical outlet with a new one and buffed the gray corrosion off the heater plug with some sandpaper. The space heater works great now.

I didn’t think to keep the worn out electrical outlet to show you here, thinking it was a rare circumstance not worth mentioning. However, as I inspected the most heavily used electrical outlets in the house I found several which were getting worn out and plugs were loose. The loose plug would often back out exposing the plug blades from the weight of the electrical cord. The bathroom and hallway plugs are the most used and abused. Think about everytime the vacuum cleaner is plugged into the hallway outlet and the cord is jerked and pulled to its full length as you work from room to room until the plug pops out. This stresses and opens the metal wipes inside the outlet over time causing a loose plug.

How to Replace a Worn-Out Electrical Outlet

This outlet by the bathroom sink was showing definitely signs of wear and wasn’t holding plugs securely. To replace the outlet, I began by:

  • Plugging in the receptacle tester which illuminated two yellow lights indicating the receptacle is wired correctly.
  • Shut off the electricity at the circuit breaker in the main electrical panel.
  • Observed the receptacle tester lights are not illuminated confirming the outlet is not powered.

When using a receptacle tester, you must test the outlet before shutting off the power because no lights on the tester can indicate an “Open Hot” condition. I could’ve used my standard voltage tester here, but since I’m wiring a new outlet the receptacle tester is more convenient.

Verify the Power is Off to the Receptacle

Verify the Power is Off to the Receptacle

Remove the Old Electrical Outlet

Remove the faceplate screw and white faceplate, then remove the two receptacle mounting screws to release it from the wall box.

Remove the Electrical Outlet Mounting Screws

Remove the Electrical Outlet Mounting Screws

Pull the electrical outlet forward from the wall box to expose the wiring:

Sidewired Electrical Outlet in Series

Sidewired Electrical Outlet in Series

Several things are apparent from the way this outlet is wired:

  • Because this outlet is in the bathroom, it’s on a 20AMP circuit with NM-B 12/2 (12 gauge, 2 conductor plus ground) wire protected by a Ground Fault Circuit Interrupter (GFCI) outlet (not shown) elsewhere in the circuit. 12 gauge wire is required for a 20AMP circuit.
  • The outlet itself is rated for 15AMPs / 125 volts, this is fine and complies with the National Electrical Code.
  • The outlet is “sidewired“, meaning the hot (black) and neutral (white) wires are fastened to the side screw terminals. (The black wires have some spray paint them from when the builder painted the walls.)
  • The outlet is a “middle of the run” wired in “series” – meaning current passes between the side terminals to the next outlet down the line. This is common practice, but parallel wiring with a “pigtail” is better.
  • The electrical wiring extends well beyond the minimum requirement of 3 inches beyond the wall box.
  • The outlet is properly grounded via the bare ground wire that is tied via a pigtail to the cable ground wires.

In brief, this outlet is properly wired.

Series versus Parallel Electrical Outlet Wiring

The following electrical outlet wiring diagram illustrates a middle-of-the-run outlet wired in series. The outlet in the above photo corresponds to the left and middle outlets in the wiring diagram. Series wiring is quicker and simpler compared to parallel wiring, however any problem with a middle-of-the-run outlet will affect all downstream outlets, i.e. outlets to the right of the bad outlet.

Electrical Outlet Series Wiring Diagram

Wiring electrical outlets in parallel with pigtail connections that are twisted and nutted together is a more reliable method which isolates the outlet from the current path, thereby reducing the chance that a problem with the outlet will affect the other outlets on the circuit. Parallel outlet wiring is illustrated in this diagram:

Electrical Outlet Parallel Wiring Diagram (Pigtails)

Disconnect the Outlet Wiring

The wires can be removed from the worn out outlet by:

  • Loosening the side terminal screws, opening the looped wire end with screwdriver tip and sliding it off the screw terminal. This is the preferred method if you’re going to sidewire the replacement outlet.
  • Or simply snipping off the wires with wire cutters as shown here.

I chose to snip off the wires because I’m going to backwire the replacement outlet and I have plenty of wire extending from the wall box. Backwiring requires straight wire ends and I couldn’t be bothered to straighten the looped ends with pliers.

Do not cut your wires if the leads extend less than 3 inches beyond wall box.

Cut the Wires Off the Old Electrical Outlet

Cut the Wires Off the Old Electrical Outlet

Electrical outlet after cutting off the wires.

Wires Snipped Off the Worn Out Electrical Outlet

Wires Snipped Off the Worn Out Electrical Outlet

This project is continued in How to Replace a Worn-Out Electrical Outlet – Part 2.

Thanks for reading,

Bob Jackson

Copyright © 2019   Reproduction strictly prohibited.


  1. Darlene May 2, 2013 at 10:07 am - Reply

    i’m in the process of changing out all of my outlets (i have copper wiring).
    some of them are exactly like you described, but some have too many wires.
    they have wires going into the backs of the outlets AND wrapped around the screws.
    for a basic outlet, why would there be more than 2 white and 2 black?

    • BobJackson May 2, 2013 at 2:24 pm - Reply

      There would be more than two cables (each cable having a black, white and ground wire) because other branch circuits are wired into the electrical outlet. I would convert a back- and side-wired outlet such as yours to a pigtail connection as a best practice.

      See How to Repair a Shorted Electrical Outlet for an outlet with a branch circuit for a closet light for an example similar to yours.

  2. Takara June 10, 2013 at 8:57 am - Reply

    I have an outlet that sparks some how it was pulled out the wall slightly and I can’t push my dresser to close or it will cause the power to go out on the main floor I want to replace it I just want to make sure that it will be safe to so so how would I use the tester when the outlet is like this

    • BobJackson June 10, 2013 at 6:26 pm - Reply

      Given your question, I assume you haven’t much experience working with electrical wiring? I’ll answer your question the way I would repair it and then recommend the I believe is best for you.

      Your wall outlet is clearly shorted which is causing the arcing and sparks. A very bad situation that could cause a fire and burn down your house. Please have it repaired without delay.

      I had a similar problem which is explained in How to Repair a Shorted Electrical Outlet.

      How I would repair the shorted outlet:
      * Hold a non-contact voltage detector next to outlet plug hole and confirm voltage is present. The non-contact voltage detector will light up and beep indicating the outlet is live. While doing this, have a helper turn Off the circuit breaker that powers the outlet and the main floor. The voltage detector light will turn off and it will stop beeping.
      * Observe the outlet no longer sparks when jostled.
      * Remove the wall plate and outlet mounting screws to release it from the wall box. Do not touch the outlet wires or side screw terminals.
      * Test the outlet wires again with the non-contact voltage detector because it could be a broken wire giving a false reading (i.e. no electricity). No electricity indicated by the voltage detector? If so continue to the next step. If voltage is present, you turned Off the wrong circuit breaker.
      * Now pull the outlet away from the wall box as far as the wires will allow.
      * Examine the wiring and figure out what’s wrong.
      * Also figure out why the wall box is loose and correct that. Some wall boxes feel “springy” due to the wall it’s side mounted to the wall stud. I don’t like that type, but there’s nothing wrong. If the whole wall box is loose, install a new box.
      * Fix the wiring problem (loose connection, broken wire, improper wiring, etc.) and install a new outlet.
      * Plug in a receptacle tester, turn on the circuit breaker and verify the new outlet is wired correctly.

      Note that a non-contact voltage detector is a different tool compared to a receptacle tester. The non-contact voltage detector is used to check if the wire is energized with electricity simply by holding the probe close to the wire or outlet:

      A receptacle tester won’t always tell you if the outlet is live (e.g. no lights will show if the hot wire is not connected to the outlet), but it will always tell you if the outlet is wired correctly:

      I use both tools on my jobs.

      Now here’s what I recommend you should do:
      If you’re not comfortable and experienced working with electricity, hire a licensed electrician to repair the shorted wall outlet and install an Arc-fault Circuit Interrupter (AFCI) in the circuit breaker panel. An AFCI would have tripped when the outlet shorted, shutting off the electricity to prevent a fire. AFCI’s are required per the National Electric Code (NEC) as of 2008.

      Please write back and let me what happens with the repair.

  3. MARY April 13, 2014 at 12:49 pm - Reply

    I have replaced a wall plug as shown in the electrical outlet series wiring diagram above. I have even check other plugs that have worked and the wiring looks the same. My tester shows power in the plug but when I plug something in the items does not work.
    Can anyone help

    • Bob Jackson April 13, 2014 at 2:14 pm - Reply

      Hi Mary,
      What was wrong with the old outlet?

      What type of receptacle tester are you using? Do the tester lights indicate the outlet is wired correctly? Note that receptacle testers can’t diagnose certain wiring faults.

      Have you verified the receptacle is wired correctly? What are you plugging into the outlet that doesn’t work?

      What is the make and model of the new outlet? Did you wire the new outlet in series or parallel? (I prefer parallel wiring because a bad outlet won’t impact the other outlets on the circuit.)

      You can send photos of the problem outlet to bob (at) – shutoff electricity at the circuit breaker, remove the two mounting screws and pull the outlet with the wires attached out from the wall box. Take photos of all sides and also looking into the wall box. Remount the outlet to the wall box so there’s no exposed wires for safety.


      • MARY April 13, 2014 at 9:05 pm - Reply

        Hi Bob,
        Thank you so much for the help. Wow, very thorough. I finally tried another new plug and wala, everything worked. Hopefully that was the real problem.

  4. valentin July 23, 2015 at 5:58 am - Reply

    I need to have something plugged in my outlet in order for the other outlets to work. If I unplug something the the power goes out in my living room and adjoining room. What’s the problem?

  5. Mary K August 4, 2017 at 6:46 pm - Reply

    Thank you. I took everything apart, thinking I would remember how to put it together, but didn’t, even though I’ve done it before. Your diagrams and photos are very helpful. (First google result was dummies–very bad illustration, hard to decipher.)

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