How to Repair Aluminum Wiring
Aluminum wiring became popular in homes built between 1965 and 1973 because it is less expensive than copper wiring. However, aluminum wiring is known to cause safety issues due to oxidation and expansion/contraction properties. As a homeowner, it's important to understand how to properly repair aluminum wiring to prevent electrical fires and other hazards.
Dangers of Aluminum Wiring
Aluminum wiring is more likely to cause issues for a few key reasons:
Oxidation
- Aluminum oxide forms on connections which increases resistance and can lead to overheating
- This oxidation process accelerates as connections are disturbed over time (during repairs, etc)
Expansion and Contraction
- Aluminum expands and contracts more than copper due to temperature changes
- This can loosen connections over time and cause arcing, sparks, and fires
Poor Terminations
- Aluminum wiring requires special connectors and installation methods
- If not properly installed, connections can loosen over time
Inspecting Aluminum Wiring
Before attempting repairs, thoroughly inspect the aluminum wiring throughout the home. Look for the following warning signs:
- Discolored or warm outlets
- Flickering lights
- Fuses that blow or circuit breakers that trip for no reason
- Light switches or outlets that don't work
- Melting insulation at connections
- A burning or ozone smell coming from outlets
Any of these could indicate an unsafe connection that needs repair.
Repairing Connections
There are three main methods for repairing aluminum wiring connections:
Pigtailing
- Twist a short piece of copper wire to the aluminum wire
- Connect the copper "pigtail" to the outlet or other termination
- Prevents aluminum-to-aluminum connections which oxidize more easily
CO/ALR Connectors
- Special connectors approved for copper-to-aluminum connections
- Contains an antioxidant paste to control oxidation
- Often considered the best DIY method
Repair Kits
- All-in-one solution containing sockets, connectors, tools
- Components designed for aluminum wire compatibility
- More expensive than individual parts but easy to install
Always follow manufacturer's instructions exactly when using special connectors and components.
Replacing Outlets and Switches
In some cases, the best solution may be to completely remove and replace:
- Outlets where the connections are burnt, corroded or damaged
- Light switches that show signs of overheating
- Any old-style outlets and switches, since they are more prone to issues
When replacing:
- Use components labeled CO/ALR for aluminum wiring
- Ensure the outlet box is large enough for the splices and connectors
Do not use traditional copper-only outlets and switches. The connections may eventually fail.
Hiring an Electrician
Due to the safety risks, consider hiring a licensed electrician if you are uncomfortable doing repairs yourself. Look for an electrician who is experienced with aluminum wiring.
Things an electrician can do:
- Thoroughly inspect for any unsafe connections
- Repair connections using best practices
- Replace old outlets/switches with CO/ALR rated ones
- Confirm proper grounding and bonding
- Evaluate the panel and breakers
- Check wiring insulation integrity
- Identify any other fire risks related to wiring
While hiring an electrician may cost more upfront, they can ensure repairs are done properly and prevent serious hazards. Improper DIY repairs on aluminum wiring can make problems even worse.
Preventing Future Issues
To minimize future issues after repairs:
- Avoid tapping circuits or overloading outlets - Additional strain can cause connections to fail
- Check for hot outlets and flickering lights - Signs of a failing connection
- Keep connections intact - Avoid disturbing wires as much as possible
- Have wiring re-inspected periodically - Detect problems before a fire hazard develops
With periodic inspections and using caution to avoid overloading circuits, properly repaired aluminum wiring can be safe for continued use. But problems can still develop over time, so be vigilant.
Overall, exercise caution when dealing with aluminum wiring yourself. Inspect all connections thoroughly, use proper repair methods, and consider hiring an electrician if you have any doubts about safely making fixes. Carefully repaired aluminum wiring will remove the fire and shock risks, allowing your wiring to be safe and reliable for years to come.