How to Diagnose and Repair Three-Way Switch Problems | All About Lights | Ask This Old House

Ask This Old House master electrician Scott Caron looks at a three-way switch issue and fixes the problem.

#ThisOldHouse #AskTOH

Tools:
Pliers
Screwdriver

Shopping List:
None

Steps:
1. Scott first gives an explanation of the three-way switch- two switches that control one light fixture.
2. There are many ways that a three-way switch can be wired, but usually power or the light fixture connect to the load side of the switch and traveler wires run between traveler screws on both switches.
3. In this case, the traveler wire and load wire were swapped and repairing the circuit involved switching them back.

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How to Diagnose and Repair Three-Way Switch Problems | All About Lights | Ask This Old House

[natzure]

Your cut away of the switch was perfect. I've seen many diagrams but seeing the actual contacts make it "real" for me. Many thanks.

[elliotdondero-pettit]

This is the only video you need to watch to repair your 3-way switch. Short, informative, concise. PERFECT!

[robtaylor]

Dude thank you so much. I was about to have a melt down trying to figure out where the error was in a 3 switch set. After several other videos with pictures and drawings, your real life actual demo was spot on. Its like the bulb went on haha. Thanks again.

[HJCF]

I like the animation how it shows the inside of the switch. Great job!

[michaelpodguski]

I recently had this issue with a light in my stairwell. Found a few videos that honed in on the issue, but lost them. A quick search led me directly to this one and the explanation was exactly what I needed to fix the issue. Took less than 5 minutes to shut everything down, reverse two wires, and get everything back in place and working correctly. Explaining the wiring principle, colors, and routing was the perfect piece to help me understand and get it done easily. Many, many thanks!

[flrockin]

Please have more explanations like the animation one. Very helpful in understanding for those us learning to be self-sufficient homeowners.

[drummereef]

Great segment! The animated diagram was a perfect example of how this works. 👍👍

[benjoetim]

Thank you for this video. After watching it I found the paired wires, identified the common wire, switched the two that were wired backward and my problem was fixed. So much easier than any other explanation that I read or watched.

[StinkyTofuHF]

I've watched plenty of 3-way switch diagnosis videos but this one is only 5ish minutes and explains it perfectly. The inside schematics and cutout did the trick. Thank you so much for an insightful video!

[mgdfx]

the best 3 way switch explanation I've seen anywhere. simple and easy to understand.

[roadrailn]

Thank other 3 way switch fix videos on youtube should be deleted now and this one saved....wasted hours watching nonsense videos and the confusing use of voltage meters and purchasing one even still being clueless to use your knowledge and explanation of where each wire inside the box should go is all i needed in under 6 minutes, i learned the connection route inside a switch even thanks to you. Great work!

[jazielpereira]

I really like this guy... the way how he explain stuff making the viewer understand what’s going on .. thank you men...

[jimealphillips]

This video was a life saver. After two hours of fighting to figure out an issue I came across this video and was done in five minutes. Thanks so much for posting it.

[LightsandFansGuy]

I know someone who had this problem showed in the video. To fix it, i did the same thing as the video: turned off the power, removed both 3 way switches from the wall boxes, switched one of the traveller wires with the common wire on one of the switches, put both switches back together, and restored power. It fixed the problem!

[TheInsuranceDudes]

Great tutorial - probably the best 3 way switch explanation ever!

[vindoan]

Best troubleshooting tips and super clear explanation. As always, I can always count on Ask This Old House videos when I ran into a problem. Thank you. Keep up the good work.

[danielmullins]

Dear Ask This Old House, I just got done fixing the same problem, having to replace a faulty, temperamental 3-way switch. Thank you so much for making my day! The only difference was that my main power wire with the bare copper ground was white. If anything else needs done to the house, I know now where I will go to.

[ib]

Thanks! This video fixed my light! SUBSCRIBED!

[systemthinker]

I can't believe it was a wire misplacement this whole time!! I would try to make a habit of keeping one swith on before I leave the house and turn the other one off. But many times I forgot and wasn't able to turn the light on at the entryway. I always thought it was just how three-way switches worked. Geeez. Thanks for the video!

[pvomero]

best 3 way video, The explaining at that the two wires in the same wrapping are the traveler wires made it very easy.