Lights out- Three way switches

By
Home Inspector with NCW Home Inspections, LLC

Lights out- Three way switches. Wenatchee and Quincy WA Home Inspection services.

One thing I try to do during a home inspection is to test that the 3 (and 4 or 5) way light switches have been wired correctly, or should I say working correctly (I actually do not see the wiring).

It is not all that uncommon to find that someone has not performed this correctly, mainly in older homes.

                                     Light out on 3 way circuit  Wenatchee Home Inspection

This seems to be one of those items that can confuse many DIY’ers. It really is pretty simple but you must understand how the "3 way" circuit works.

Hold on Mr. Home Inspector, why are they called "3-way circuits" when I have only 2 switches?

Well friends this has a bit of history to it. This goes back to the days of yore, to the days of Mr. Edison when this new trade of electrician comes into being and one way they would bid the job is by “drop points”.  A drop point could be a switch, a junction or a load point etc... So a regular switch would have 1 switch and one load, or known as a “2 way” switch.  So then we add that second switch and now we have 2 switches and 1 load and the term “3 way” comes into play. Makes sense right?

In simple terms a 3-way circuit is a lighting circuit that allows a light fixture to be controlled by two wall switches in different locations. They do this by switching the hot wire (load) toward the light on two alternate wires called "travelers".  The heart of this circuit is the 3-way switches.

Now there are several ways to “skin the 3 way cat” but I will show the most common way.

3 way switch variations

                           3 way light circuit Quincy WA Home Inspection
As you can see in this illustration we have the hot wire (black) come into the first 3-Way switch then we have two travelers leaving the switch going to the next 3-Way switch then a single wire out to the light. The neutral (white) is spliced and travels independently to the light to complete the circuit.

What makes this more complicated for many is just where the light is placed in the wiring system but the principle is exactly the same.

There are also 4-way, 5-way, and 10-way circuits. These really are just the same except we place 4-way switches between the two 3-way switches in the circuit.

                                4 way light circuit Quincy WA Home Inspections

Now wasn’t that easy?

But in all reality if you do not understand how these systems work you are much better off hiring a professional. Electricity can kill or burn your home down.

 

“If you think it's expensive to hire a professional to do the job, wait until you hire an amateur.”

Red Adair


NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service
www.ncwhomeinspections.com                                               509-670-9572

close

This entry hasn't been re-blogged:

Re-Blogged By Re-Blogged At
Spam prevention

Accessibility option: listen to a question and answer it!

To submit the form,
drag the folder to the circle on the side.

Type below the answer to what you hear. Numbers or words, lowercase:

Topic:
ActiveRain Community
Location:
Washington Grant County
Groups:
Puget Sound - WA Real Estate
Home Inspectors across the country
Active Rain Newbies
Professional Home Inspectors
Almost Anything Goes
Tags:
quincy wa home inspection
wenatchee home inspection
electrical inspection
4 way switches
3 way switches

Comments 10 New Comment

Anonymous
Post a Comment
Spam prevention

Accessibility option: listen to a question and answer it!

To submit the form,
drag the robot to the circle on the side.

Type below the answer to what you hear. Numbers or words, lowercase:

Show All Comments
Rainmaker
288,896
Fred Hernden
Tampa Bay area Home Inspector
Superior Home Inspections - Greater Tampa Bay Area

Don, nice job of explaning the 3 way. This is why you have to have a healthy respect for electricity and it's properties! Even something as simple as replacing a bad 3 way switch.

February 27, 2013 06:34 AM
Rainmaker
692,519
Clint Mckie
Desert Sun Home, Comm. Inspection 1-575-706-5586
Desert Sun Home, commercial Inspections

Hi Donald,

There are so many of these switches that are wrong.

I had a bath the other day that used to have a exhaust vent with a light. It was still wired for the vent and light but the vent and light was removed when the home was flipped.

With the bath in the middle of the home, it needs to have a working vent. No way around that fact.

Have a great day in the Greater Wenatchee area.

Best, Clint McKie

February 27, 2013 06:38 AM
Rainer
277,079
Steven Cook
- Pierce, King, Kitsap, Thurston, Mason Counties
No Longer Processing Mortgages.

Don -- thanks for the very  useful information and illustration regarding the 3-way switch situation.  I hadn't heard of the ones higher than that.

February 27, 2013 11:46 AM
Rainmaker
1,217,985
Jay Markanich
Home Inspector - servicing all Northern Virginia
Jay Markanich Real Estate Inspections, LLC

I had a three way just yesterday that only worked when one was in the up position!  I wish I had your diagram to show my clients during the inspection!  You gots the best diagrams.

February 28, 2013 04:04 AM
Rainmaker
358,433
Donald Hester
NCW Home Inspections, LLC
NCW Home Inspections, LLC

Fred, Thanks. Even some of the simple things is beyond many ;)

Clint, So true.

Steven, Thank you. once you passed the 4 way it is the same configuration just adding more 4 way switches.

Jay, Pictures do tell a story.

February 28, 2013 05:29 AM
Ambassador
1,068,226
Charles Buell
Seattle Home Inspector
Charles Buell Inspections Inc.

Good post Don.  Most people can handle this installation until the light is "between" switches :)  I warn my client that in many cases all combinations may not be tested in the context of the home inspection.

February 28, 2013 06:12 AM
Ambassador
1,638,058
Fernando Herboso - Broker for Maxus Realty Group
301-246-0001 Serving Maryland, DC and Northern VA
Maxus Realty Group - Broker 301-246-0001

I must be one of the few here in the rain that could follow your charts. . 

but why will someone attempt at doing this on their own?

a weekend do it yourself-er bad paint job. .just looks bad

but  bad wiring on a 3-way switch could be a fire!

March 01, 2013 06:36 AM
Rainmaker
548,223
Than Maynard
Broker - Licensed to List & Sell - 405-990-8862
Coldwell Banker Heart of Oklahoma

That is why they have to get an electrical license. They get trained and paid to figure that out.

March 01, 2013 08:34 AM
Rainmaker
358,433
Donald Hester
NCW Home Inspections, LLC
NCW Home Inspections, LLC

Charlie, That does send people for a loop.

Fernando, That does apply to many things with the electrical system.

Than, Very true.

March 01, 2013 09:42 AM
Rainmaker
626,589
James Quarello
Connecticut Home Inspector
JRV Home Inspection Services, LLC

Your post was about electrical switches, here I was expecting some thing else ;)

March 03, 2013 04:48 AM
Anonymous
Post a Comment
Spam prevention

Accessibility option: listen to a question and answer it!

To submit the form,
drag the tree to the circle on the side.

Type below the answer to what you hear. Numbers or words, lowercase:

Show All Comments
Rainmaker
358,433

Donald Hester

NCW Home Inspections, LLC
Home Inspection Services and Inspection Questions
*
*
*
Spam prevention

Accessibility option: listen to a question and answer it!

To submit the form,
drag the cat to the circle on the side.

Type below the answer to what you hear. Numbers or words, lowercase:

Additional Information