Aluminum wiring thru house

[Rick Beeman]

Finding homes using aluminum wiring throughout is not hard to do in my area. I'm looking for issues that I should check for compared to copper wiring. Like, how do you know if the outlets are rated for aluminum without taking them out of the wall? can you tell anything by just removing the cover plate? Size of wire should increase accordingly , going up 1 size everywhere compared to copper, anything else? fuse sizes?
thanks
Rick

[Gary Burnett]

Rick,
I can usually spot the CO/ALR stamp on the receptacles at the top of bottom of the ears. I sometimes have to scrape the paint off to see if they are CO/ALR. Switches may have the stamp on the ears and at times I have had to remove the switch and it is printed on the back. I also look for the purple wire nuts at the pigtails and not yellow or red which are not for aluminum to copper. The purple wire nut is an Ideal #65 and sometimes they use a purple AlumiConn connector. If the home was remediated prior to the early 90's the connector won't be purple since they didn't have an approved copper to aluminum connector back then. When you remove the coverplate if you see aluminum to one marked CU/AL that's wrong. Some electricians don't like the CO/ALR outlets but they are still listed. Many don't like the wire nut and recommend the AlumiConn connection.

This picture has CO/ALR stamped at the bottom of the receptacle.

[Rick Beeman]

Thank you for the info

[Jerry Peck]

A potential issue with removing devices on aluminum wiring is one of the issues with aluminum wiring - the older alloy didn't take bending and rebending very well ... the older aluminum wires have a tendency to break.

Just something to consider.

[Bill Kriegh]

Do you guys really need to be messing around with aluminum wiring and devices?

First, as Jerry pointed out, just the act of moving the wire by removing a device from the box can break, or severely damage (almost break but not quite, creating a hot spot) the wire at the connection points - often at the point the wire was stripped due to nicks in the conductor from using the wrong tool.

Another issue is that because alm. wire expands and contracts quite a bit, wire-nutted connections that may have been OK before being disturbed come loose inside the wire nut.

I think you've done your job if you say there's aluminum wiring and it needs evaluation by a professional if inspection goes beyond removing the cover.

[John Kogel]

Right, don't pull any switches or receptacles unless you are a certified electrician hired to work on the seller's house. Pulling a few covers doesn't usually cause any damage, and then take some good pictures.
Always recommend having an electrician do a full check of all the Al circuits and fixtures. I would say it should be done every 10 years, or have copper wiring installed.