Introduction: How to Replace a Single-Pole Light Switch (Residential Applications Only)
You flip a light switch, and nothing happens. You change the lightbulb, but that didn’t do the trick. What is the problem? It is most likely a bad light switch. Light switches are mechanical devices that interrupt current to other electrical devices. Like all mechanical devices with moving parts – they can go “bad”. Switches are no exception to this rule.
Many people do not have the electrical knowledge needed to replace a light switch (not a problem), or do not want to pay an electrician hundreds of dollars for such a simple task. Look no further, this Instructable will teach you how to save time, money, and headaches. It will also give you a rewarding feeling of achievement when you complete the task successfully. Continue reading below to begin.
Step 1: Tools, Materials, & Duration
1. Headlamp or Flashlight (optional)
2. Philips-Head Screwdriver
3. Flathead Screwdriver
4. Linesman Pliers or Pliers (optional)
5. Wire Stripper (optional)
6: Switch Plate. $1.00
7. 120V Single Pole Switch. $1.00
Safety Items List:
Voltmeter or Circuit Tester (optional, not pictured)
Approximately 5 -30 minutes
Step 2: Warnings
Warnings and Cautions:
- These instructions are intended to be used in residential applications only.
- To avoid fire, shock, or death: TURN OFF POWER at circuit breaker.
- Switches are to be installed and/or used in accordance with electrical codes and regulations.
Step 3: Get to Know the Single-Pole Switch
For this instructable's purpose, we do not need to know every component and function on the switch itself. If you want to learn more above switches, please visit https://learn.sparkfun.com/tutorials/switch-basics/all .
1. Ground Screw: Green screw. Where the bare copper wire gets attached.
2. Terminal Screws: Gold/bronze colored screws. Where the wire from the power source and to the light are attached (usually black wires).
3. Yoke: Stainless steel. Each end is in the shape of a “Y”.
4. Backstab Holes:Small holes to poke wire ends in to rather than curling them around the terminal screws. These holes are just an alternative way to wire a switch without bending curls on the ends of each wire. Curls will be discussed in "Step "
Step 4: Finding the Circuit Breaker Panel
Make sure you have already tried changing the fixture's light bulb(s) before preceding.
Look for and find the circuit breaker panel in the residence.
Tip: Circuit breaker panels can be found in utility rooms, garages, basements, and other locations. Be patient and observant while looking for this steel can.
Step 5: Inside the Panel Door
Open the panel door and read the breaker labels on the inside cover. Look for the “Main” label on the door’s inside and throughout the breakers (click on image above).
Tip: Labels inside the panel door are room and appliance names.
Step 6: TURN OFF THE "MAIN" CIRCUIT BREAKER
This is the safest, easiest, and fastest method to ensuring the power is 100% off. When turning off the main breaker (pictured above, and in step 5), a firm press is required to toggle the breaker to the “OFF” position.
Tip: Be aware that turning off the main breaker will turn off everything that is electrically powered in the house.
Tip: The main breaker is often times located at the top of the circuit breaker panel (pictured in "Step 5") and will have writing saying “100” or “200” directly on the switch (pictured above).
Tip: Breakers work like light switches and are labeled “ON” and “OFF”.
Step 7: Testing to See If Power Is "ON"
Go to the location of the switch you are replacing. Toggle the switch “ON” and “OFF” to see if the light turns on. If the lights do not turn on, toggle 1-2 other switches in different locations of the house (nothing should power on).
If any lights do turn on, go back to “Step 6”.
Step 8: Using a Circuit Tester to Test for Power (Optional)
As a secondary safety measure, you can use a circuit tester to determine if there is power to the switch.
Tip: Read circuit tester instructions on how to use your tester. If there are no instructions, most testers will blink red or make an intense static noise when you hold it within 1-2 inches of a powered switch.
Step 9: Remove the Switch's Cover
Remove the switch cover with a flathead screw driver (pictured above).
Tip: Set the cover’s screws in a place where they will not get lost.
Step 10: Remove Switch From Box
Power has been confirmed to be off by toggling the light switch(s) or by using the circuit tester.
You can now use your philips-head screwdriver to remove the switch from the box it is attached to (pictured above).
Step 11: Pull Switch Out of Box
Gently pull the switch out as far as the wires allow, or enough to see where the wires are attached to the switch’s ground and terminal screws. TAKE A PHOTO(S) OF THE SWITCH. These photos will help if you forget how the switch was originally wired.
Tip: If there are wires pushed into the backstab holes (shown in "Step 3"), cut the attached wires with wire stripper or lineman pliers one at a time and as close as possible to where the wires are pushed in to the switch. Then re-strip the wire sheathing back about .5 inches on the two wires with wire strippers.
Step 12: Un-Screw Wires From Screws
Un-screw wires from the screws on switch with the philips-head screwdriver (pictured above). Always un-screw the bare copper wire last.
Tip: The most effective way to do this is by completely removing the screw from the switch so that the wires still maintain their “curl”. The screws will fall to the ground, and will no longer be needed.
Tip: If wires do not maintain their curls, re-bend them back into place with a regular pliers (pictured above)
Step 13: Reconnect Wires to New Switch
Once the wires are all disconnected from the bad switch, reconnect them to the new switch in the same fashion they were connected before. You can look at the photo(s) you took in “Step 11 ” for reference. Always connect the bare copper wire to the green ground screw first (pictured above). The other two wires can go to either terminal screw on the switch’s side.
Tip: If the switch had the wires “pushed in” to the back holes, re-push the stripped wires in to place firmly.
Tip: Make sure wires are connected securely (screwed down tightly).
Step 14: Attach the Switch Back to the Box
Maneuver the switch back into its original place. Screw the switch yoke screws to the box with philips-head screwdriver.
Tip: To make sure the switch sits flush, only screw in the switch until the yokes are flush with the wall or box (pictured above). If you have screwed in the switch to tightly the yokes will be bent. You can tell if you have bent the yokes by the switch having a "sucked-in" appearance.
Tip: If you have bent the yokes, unscrew the yoke’s screws slightly and pull on the switch until straightened or as close to straight as possible. Then gently screw the yokes back in until flush.
Step 15: Re-Attaching the Switch's Cover
Place the switch cover on the switch without the flathead finish screws. Proceed to screw in one screw at a time with the flathead screwdriver until both finish screws are completely in (pictured above).
Tip: If you have screwed the cover on too tightly, the cover will appear “sucked-in”. Do not finish the switch with a “sucked-in” cover. Gently unscrew the finish screws until the cover appears flat.
Step 16: Turning Power Back "ON"
Make sure the switch is in the “OFF” position (pictured above). Go back to circuit breaker panel and turn the main breaker to the "ON" position.
Step 17: Check to See If the Switch Works
Return to the switch. Toggle the switch into the “ON” position. Your light should now be on. You have successfully wired in a new single-pole light switch!
Tip: If the light does not turn on there is no need to panic. Return the switch to the "OFF" position, and consult with a licensed electrician to further troubleshoot. When this happens, there is usually a problem further down stream than the switch (like at the light fixture).