How to replace a 3 way switch

 

How to replace a 3 way switch

I have created step by step instructions on how to replace a 3 way switch. (with pictures)

What is a 3 way switch? A 3 way switch is a switch that can control one light fixtures or several light fixtures in more than one location. Lots of homeowners call them 2 way switches but they are really 3 way switches. 3 way switches can be used for more than two locations by using one or more 4 way switches. I wont get into all that on this article. This article is just to explain how to replace a 3 way switch.

Important note: Always comply with the NEC (National Electrical Code) your local and state laws before starting. Some city offices or city libraries might give you access to or help you out with an NEC book. You can even call your local building inspector to find out if you can do your own electrical. Your work might have to be inspected. Do your own research to see if you can DIY your own electrical and what codes are in place.

Working on live circuits is dangerous and not recommended. Always turn off the circuit and check for power before working on anything electrical.

Tools

Here is a list of basic tools for doing this electrical project

    • Volt Meter (if you’re going to be doing your own electrical you really should invest in a decent volt meter.
    • Wire Strippers
    • Needle-nose pliers (you will only need these to bend loops in the wires if your strippers don’t have holes for loop makers)
    • Flat Blade
    • Philips
    • Drill (recommended, but optional)


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Materials

They make Residential grade, Commercial  grade, hospital grade, you can get just about every color imaginable too. (for a price of course)

A standard 15-amp 3 way toggle switch could cost anywhere from $0.68 to an decorator 3 way switch for about $4.00. Expect to pay a little bit more to buy them individually too. You can get boxes of 10 (contractor pack or bundle) for a discounted price per switch.

Most cases you will only need a 15-amp switch. 15-amp switches are made for circuits not exceeding 15-amps such as a 15-amp breaker or fuse. While a 20-amp switch is made for circuits not exceeding 20-amps such as a 20-amp breaker or fuse. I can’t think of a time you would be switching a 20-amp load in your house.

Follow These Steps

Here is what I will be covering
1. Turning off power to circuit
2. Removing cover plate from 3 way switch
3. Removing the 3 way switch from wall
4. Removing wires from 3 way switch
5. Installing wires to new 3 way switch
6. Installing 3 way switch in wall
7. Installing cover plate to 3 way switch
8. Returning power to circuit
9. Checking 3 way switch

Step One

breaker in the off position

First thing you want to do is turn off the power. Never work on live circuits. To properly turn off the circuit, turn on the light from the switch that you will be working on. Then go to the electrical panel and turn off the breaker for that circuit. Tip: Leave a note or tape over the breaker and write “working on this circuit. Leave off.” If your panel labels are unclear or hard to read then turn off one at a time until the light/circuit that you are goes off. Double check by turning the switch off and on then back to the off position.

Step Two

removing cover plate image

Now that the power is off, remove the cover plate. You will need a flat head screwdriver for this.

Step Three

image of removing 3 way from wall

Next unscrew 3 way switch from the wall using a phillips screwdriver or your cordless drill. Here is a TIP, If the tabs on the switch have been painted over take a box knife and cut around the tabs so when you remove the switch it wont pull your paint.

Step Four

back of 3 way switch image

Now pull out the 3 way switch. On the switch there will be 4 screws, two gold screws (travelers), one black screw (common), and a green screw (ground). Remember what wire is hooked to the common “black” screw. The wires that are attached to the travelers “gold” screws can swap and the switch will still work properly.

image of removing wires from 3 way switch
If the wires are wrapped around the screws then loosen the screws and remove the wires. If the wires are pushed into the back of the switch then you will need to cut the wires as close to the back of the switch as possible.

Step Five

back of 3 way switch image

3 way switch

back of single pole switch image

Single pole switch

 

 

 

Look at the new 3 way switch, there will be the same two gold traveler screws, a black common and a green ground screw. If there is only two gold screws and a green ground screw then you only have a single pole switch.

bending wire
There is a wire strip gauge on the back or side of the new 3 way switch. Take your wire strippers and strip the wires to the length indicated on the strip gauge. You then take your needle nose pliers or use the loop bender on the strippers to bend a loop in the wires.
It is only important to remember the wire you took off of the black screw, needs to go on the black screw on this switch. The wires for the gold screws can go to ether of the gold screws. Attach the loop so that the end of the loop is headed clockwise around the screw. Tighten all the screws well, you don’t want any loose connection when it comes to electricity.

NOTE: If you are using a white wire for power/hot wire you need to mark both ends of the white wire with black or red tape to show the next person who works on that switch or the other switch that the white wire is not a neutral.

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Step Six

image of installing switch

Bend the wires neatly as you push the switch into the box. Make sure that the bare ground wire is not touching any bare metal parts of the switch. Using your phillips or cordless drill tighten the switch to the wall tight enough that it wont wiggle side to side but not too tight because the cover plate wont fit right.

image of removing 3 way from wall


 

Step Seven

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Install cover plate using a flat blade screwdriver. Tip: Some cover plates are breakable so when tightening the cover plate be careful and don’t over tighten the screws or the plate will break.

Step Eight

turning on breaker

It’s time to restore power back to the circuit. Remove your note and turn the breaker back on.

Step Nine

It’s time to check your work. Check by turning the light ON from one location then OFF from the other location then back ON from the first location and OFF again at the second. If you did it right it will work like normal. If not you have mixed up the common wire with one of the travelers and you will have to turn the power off and pull the switch out and make the adjustment.

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Here is what I have covered
1. Turning off power to circuit
2. Removing cover plate from 3 way switch
3. Removing the 3 way switch from wall
4. Removing wires from 3 way switch
5. Installing wires to new 3 way switch
6. Installing 3 way switch in wall
7. Installing cover plate to 3 way switch
8. Returning power to circuit
9. Checking 3 way switch

And that’s it!
You’ve done it!
Stand tall, be proud, and tell all of your friends to please like Wiring How To’s facebook page or share this article with your followers I’d really appreciate it. Cheers!

 

Need more information?

How to wire a single pole switch

How to wire an outlet

How to wire a GFCI

How does a GFCI work

Switch wiring diagrams

Outlet wiring diagrams