Symptoms
- Wires behind outlets and switches are silver-colored rather than copper
- Outlets or switches feel warm, flicker, or have failed more than expected
- Home was built or the electrical system was last updated in the late 1960s to early 1970s
Likely causes
- CommonOriginal aluminum wiring never upgradedAluminum was commonly used for branch circuits during a copper shortage in that era.
- CommonAluminum wire connected directly to devices not rated for itAluminum expands and contracts differently than copper, which can loosen connections at standard outlets and switches over time.
- PossibleCorrosion at aluminum-to-copper connectionsImproperly treated connections between aluminum and copper can corrode and overheat.
What to do
- Do not attempt to identify or work on aluminum wiring connections yourself.
- Have an electrician confirm whether your home has aluminum branch wiring, since it's not always obvious.
- Ask about copper pigtailing with connectors rated for aluminum-to-copper connections (a common, less invasive fix).
- Consider having devices connected to aluminum wiring replaced with ones specifically rated for aluminum ('CO/ALR').
- Prioritize any outlet or switch that feels warm or shows discoloration for immediate attention.
- Ask your insurance company if they require any specific remediation for aluminum wiring.
- Get a full evaluation before any major renovation that will disturb these circuits.
When to call a pro
Have a licensed electrician experienced with aluminum wiring evaluate your home and recommend pigtailing or other approved fixes.
Safety
Use caution
Don't work on aluminum wiring connections yourself; loose aluminum connections are a known fire risk and need proper remediation methods.