Introduction
Rewiring outlets and lights in your home can seem daunting, but with proper precautions it is totally doable as a DIY project. I have successfully rewired several rooms in my home over the years and have learned a lot through trial and error. In this guide, I will walk you through the complete process step-by-step, from gathering the right tools and materials to connecting the wires properly and safely.
The most important thing is to make safety your top priority. Working with electrical wiring can be extremely dangerous if proper precautions are not taken. Make sure to turn off the main breaker before doing any work, and double check that the power is off using a non-contact voltage tester. It's also crucial to follow local electrical codes and use the proper gauge wiring for your home's electrical system.
While rewiring does take some time and effort, the savings compared to hiring an electrician are significant. And there's a real sense of satisfaction that comes from upgrading the electrical system in your home with your own two hands. Let's get started!
What You'll Need
Before getting started on any electrical project, it's essential to gather all the necessary tools and materials. Here's what you'll need on hand:
- Non-contact voltage tester - To double check the power is off before working
- Phillips and flat head screwdrivers - For removing outlet and switch cover plates
- Needle nose pliers - For pulling and connecting wires
- Wire strippers - To strip insulation off wire ends
- Electrical tape - For insulating wire connections
- Wire nuts - For joining copper wires together
- Electrical boxes and braces - If replacing outlets or switches
- NM-B Wire - New copper wiring with ground wire
- Wall plates - Match your home's existing switches and outlets
It's also a good idea to have a helper when rewiring so you have an extra set of hands. Make sure to wear safety glasses and work gloves as well.
Turning Off the Power
Before touching any wiring, the power must be turned off at the main breaker. The main breaker is usually located in the garage, basement, or a closet panel and controls power to the entire house. Turn it to the "Off" position so the switch is no longer raised.
I cannot emphasize enough how vital it is that the power is OFF. Getting shocked by live wires can result in severe burns or even death. Always double check with a non-contact voltage tester that the wires have no power flowing through them. Test the wires inside the electrical boxes as well as at the outlets or switches. Verify multiple times that there is absolutely no live power.
If you have any doubt about whether you have the right breaker or main power switch, it's best to contact an electrician to locate and turn off the power for you. Working on live wires is extremely foolhardy.
Removing Old Outlets and Switches
With the power definitively off, you can now remove the cover plates from any outlets and switches you'll be replacing using a screwdriver. Take note of how the current wires are connected so you can replicate the connections with the new wiring.
Unscrew the outlet or switch from inside the electrical box and carefully pull it out, making sure to support the wires. You may need to use needle nose pliers to grip and loosen the small terminal screws to free the wires. Label wires as you remove them so you know exactly where each one was originally connected.
If the electrical box itself is damaged and needs replacing, you'll have to remove all wires from the box, unscrew it from the studs, and install a new old work or new construction box depending on your situation. Use box clamps or brackets to securely fasten it.
Pulling New Wires
Now comes the task of running new NM-B electrical wire from your circuit breaker panel to each outlet or switch. Start by turning the power back on at the main breaker so any existing wires are energized - this makes them easier to locate.
Turn the power back off after you've identified the wires you need. Use a drywall saw to cut holes between studs to route your new NM-B wires through. Try to run all new wiring through walls horizontally or vertically inside the existing wall cavities. Pull about 6 to 12 inches of extra wire out from the box openings.
Be sure to get the correct gauge wire for your home's electrical system. Most modern homes use 14 gauge for 15 amp breakers and 12 gauge for 20 amp circuits. The wire thickness must match the amperage to avoid overheating.
If you need to run wire over ceilings or floors, use metal conduit or clamps to safely secure them. Never just lay exposed wires across open spaces.
Connecting the New Wires
Now comes the slightly tricky part - connecting your new wires properly. Refer to your labels to copy the previous connections.
Start with the hot wire coming from the breaker, marked with black insulation. Connect it to the shorter slot of the outlet using a small screwdriver. Place the neutral wire (white insulation) into the longer neutral slot, matching your old connection diagram.
Ground wires connect to the green screw or clamp on outlets and switches, while bare copper grounding wires get attached to the metal electrical boxes themselves. Make sure every new box and device is properly grounded for safety.
Use wire nuts to join the old and new wires for each connection point. Wrap connections with electrical tape for additional insulation. Take your time and double check each one. Getting the hot and neutral wires swapped can fry appliances and electronics.
Once all connections are made securely, tuck the wires neatly into the boxes so they're not pinched or stressed when devices are installed. Screw switches and outlets back into place along with cover plates.
Turn Power Back On and Test
You're almost finished! Now it's time to head back to the main breaker and carefully turn the power back on to the house. Go around and test each outlet and switch to verify proper operation. Plug in lamps or devices and turn lights on to confirm functionality.
If a breaker immediately trips, you likely have a short somewhere from wires touching. Double check connections and ensure bare copper or ground wires are not contacting hot wires. Also verify your wire gauges - incorrect sizing can cause shorts.
Take the time to fix any issues before reconnecting power. If needed, flip the breaker on and off quickly to help locate any problem areas. The circuit should power on without issue when wiring is completed correctly.
Once everything checks out, install faceplates and you can call your rewiring project a success! I find it extremely rewarding to upgrade my home's electrical system myself rather than paying an electrician. Just be sure to always exercise caution when working with wiring and electricity.
Safety Tips
- Turn main power OFF and verify it's dead with a voltage tester
- Wear protective eyewear and gloves when handling wires
- Double check all connections are tight and well insulated
- Use wire nuts and electrical tape on all wire junctions
- Never work on live wires - this risks shock and electrocution
- Match wire size to breaker amperage to prevent shorts
- Ensure new boxes and devices are properly grounded
With the right safety precautions, you can tackle basic outlet and light rewiring yourself. But if a project is beyond your skill level, don't hesitate to call a licensed electrician. There's no shame in knowing your limits when dealing with dangerous electrical systems. Stay safe and good luck with your upgrades!