Aluminum wiring: the risks and what fixes it
Aluminum branch wiring is a fire risk at its connections, not along the wire. It was used in roughly 2 million homes built between 1965 and 1973. The fix is a repair at every connection, or new copper wiring.
Aluminum wiring is not a rumor. It is a documented fire hazard that the federal Consumer Product Safety Commission (CPSC) has warned about for decades. It is also fixable, and many homes live with it safely after a proper repair.
Why aluminum wire causes trouble
Aluminum expands and contracts more than copper when it heats and cools. Over years, that loosens the screw connections at outlets, switches and fixtures. A loose connection heats up, and aluminum also forms an oxide film that makes it worse. The result can be arcing, and the CPSC warns that a serious fire can start and spread inside the wall before anyone notices.
The wire itself is not the weak point. The connections are. CPSC also notes that failing connections seldom show warning signs, so a house with none can still have a problem.
Which houses have it
The CPSC estimates about 2 million homes were built with aluminum branch wiring between 1965 and 1973. That period matches the housing boom in many SoCal cities. Later CPSC material notes aluminum cable can turn up in homes wired from 1965 into the mid-1970s, so treat the dates as a guide, not a hard line.
Two clarifications:
- The concern is aluminum branch circuit wiring on 15 and 20 amp circuits. Large aluminum cables used for service entrances and some feeders use different methods.
- Cable marked “copper-clad” is not the same as solid aluminum.
Warning signs
- Outlet or switch cover plates that feel warm
- Flickering or dimming lights
- Outlets or circuits that stop working
- A smell like burning plastic near an outlet or switch
- Sparks or buzzing
If you notice any of these, stop using that circuit and have an electrician look. See hot or burning-smell outlets.
How to check your house
- Look at cable in the attic, garage or basement for “AL” or “Aluminum” printed on the jacket.
- Check outlets. Devices marked CO/ALR are made for aluminum wire.
- Ask a licensed electrician or home inspector. Many can confirm in a short visit.
Repair options
| Option | What it does | Notes |
|---|---|---|
| COPALUM crimp | Joins a copper tail to each aluminum wire with a crimp that forms a permanent connection | The CPSC describes it as a complete, permanent repair. Only electricians trained by the maker can use it, so ask what is available near you. |
| AlumiConn-type connectors | Listed connectors that join copper pigtails to aluminum | The CPSC lists it as an acceptable alternative to COPALUM. |
| Rewire in copper | Removes the aluminum branch wiring | The most complete fix and the most disruptive. |
| Twist-on connectors | None | The CPSC rates these as inadequate. Do not use. |
The CPSC says a repair has to cover every connection that involves aluminum wire, including outlets, switches, fixtures and junction boxes in the house. A half repair leaves the hazard in place. Which method your city and insurer accept can vary, so ask before you pick one. Whatever the method, a licensed electrician should do the work under a permit. The aluminum wiring service page covers the process.
What the fix costs
Prices depend on how many connections the house has. For a whole house:
- A full copper rewire runs $8,000 to $20,000 in a typical SoCal range as of October 2026, for a home of 1,500 to 2,500 square feet, with patching extra. See whole-house rewire cost.
- A partial rewire, for example the kitchen and bedrooms only, is usually $3,000 to $8,000 by desk estimate. See partial rewire.
Connector repairs are priced by the number of connections. Ask for a count and a per-connection price on the quote, and ask which method will be used.
Aluminum wiring and selling your home
Buyers’ inspectors often flag aluminum wiring, and some insurers ask about it. A written statement from a licensed electrician describing what was repaired helps in a sale. The home sale electrical inspection guide lists what else tends to come up.
What to do this week
- Find out whether your house was built from 1965 to the mid-1970s.
- Check the cable jacket where you can see it.
- If you find aluminum, ask an electrician for a connection count and a repair quote, and decide between a connector repair and a rewire.
- Stop using any outlet that is warm, buzzing or smells hot.
The rewiring hub compares the options in more detail.
Questions people ask
How can I tell if my house has aluminum wiring?
Look at the cable jacket in an attic, garage or unfinished basement for the letters AL or the word Aluminum printed on it. Older cable has silver-colored conductors instead of copper. A cable marked copper-clad is different. If you cannot find a cable to read, an electrician or a home inspector can check the panel and outlets.
Do I have to replace all the aluminum wiring?
Not always. The safety problem is at the connections, so a repair done at every outlet, switch and splice can fix it without opening walls. Rewiring with copper removes the issue entirely and costs far more. Which path fits depends on the house, the budget and what your insurer and inspector accept.
Are twist-on wire nuts a safe fix for aluminum wiring?
No. The Consumer Product Safety Commission has found that standard twist-on connectors are inadequate for joining copper to aluminum. Use only connectors made and listed for this repair, installed by an electrician who has used them. Switches and outlets on aluminum circuits should be marked CO/ALR.
Will aluminum wiring affect selling my house or insurance?
It can. Some buyers' inspectors flag it, and some insurers ask about it or want proof of a repair. Rules differ by company, so ask yours before you list or renew. A written report from a licensed electrician showing the repair is useful paperwork in either case.
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