Why it matters
Aluminum expands and contracts more than copper, oxidizes, and creeps under pressure. Over years, connections at outlets, switches and splices loosen and develop resistance. That heats the connection, which can start a fire inside a wall box. The U.S. Consumer Product Safety Commission has published guidance on the hazard for decades.
Warning signs
- Warm cover plates on outlets or switches.
- Flickering lights.
- Burning plastic smell.
- Outlets or switches that stop working.
- Discolored outlets.
Repairs
| Method | What it is | Notes |
|---|---|---|
| Full rewire with copper | Replace branch wiring | Most permanent; most invasive |
| COPALUM crimp | Copper pigtail cold-welded to aluminum with a special crimp tool | Recommended by CPSC; requires trained installer |
| AlumiConn connector | Set-screw lug connector rated for aluminum-to-copper | Recognized by CPSC as an alternative |
| CO/ALR devices | Outlets and switches rated for aluminum | Limited, partial measure |
Standard twist-on connectors and push-in connectors are not considered an adequate repair.
For buyers
If the inspector reports aluminum branch wiring, get an electrician to evaluate it and quote a recognized repair before your contingency expires.
Common questions
How do I know if my house has aluminum wiring?
Look at the cable jacket in the attic, garage or panel for the word "ALUMINUM" or "AL." In the panel, aluminum conductors look silver rather than copper colored. An electrician can confirm.
Will insurance cover a house with aluminum wiring?
Some insurers decline or surcharge homes with original aluminum branch wiring. Documentation of a recognized repair by a licensed electrician often resolves it.