Dead outlets, warm switch plates and lights that flicker for no clear reason are ordinary repair calls in most homes. In a home with aluminum branch wiring they deserve a closer look. A good share of Miami's housing was built or rewired in the years when aluminum wire was common, and its connections fail more often than copper ones. Here is what the U.S. Consumer Product Safety Commission says about it, and what a lasting repair involves.
How much of each Miami-Dade city’s housing dates from those years is in our study of when Miami-Dade’s homes were built.
Which homes have it
The CPSC's publication Repairing Aluminum Wiring explains that a copper shortage in the mid-1960s led builders to use aluminum wire for ordinary 15- and 20-amp circuits, and that cables installed between 1965 and the mid-1970s, in new homes, additions and rewired circuits, may contain aluminum. Homes built before 1965 are unlikely to have aluminum branch wiring unless they were added to or rewired in that period.
Aluminum is still used today for large feeders, service cables, dryers and ranges. That is a different product, and CPSC's repair guidance does not cover it. This guide is about the smaller branch circuits that feed outlets, switches and lights.
Why the connections fail
The CPSC describes several deterioration processes at aluminum wire connections that increase resistance, with damage that is cumulative, so connections overheat, sometimes at hazardous levels. The failures happen at outlets, switches, splices, and connections to appliances.
The number CPSC cites is striking: a national survey for the Commission found that homes built before 1972 and wired with aluminum were 55 times more likely to have one or more connections at outlets reach fire hazard conditions than homes wired with copper.
Warning signs
CPSC is direct that failing aluminum connections seldom give easy warning, and can overheat without any prior signs. When there are signs, it lists:
- Face plates on outlets or switches that are hot to the touch.
- Flickering lights.
- Circuits that do not work.
- The smell of burning plastic at outlets or switches.
Its advice if you notice any of these is to have a qualified electrician find the cause, and not to try it yourself. If one of these is happening now, switch off the breaker for that circuit if you can identify it, and see our guide to burning smells and buzzing.
How to tell if you have it
CPSC says the cable jacket is marked "AL" or "ALUMINUM" every few feet, and that markings are visible where cable is exposed, such as in attics and garages. It also notes that cable marked copper-clad aluminum is a different product not covered by its repair recommendations. Many Miami homes are concrete block with few places where cable is exposed, so the practical answer is often an electrician checking at the panel and at a few devices.
What CPSC accepts as a permanent repair
CPSC recommends a permanent repair for aluminum-wired homes that have not been remediated, and recommends hiring a qualified electrician to do it. It accepts three methods:
- Replacing the aluminum branch wiring with copper. The most complete fix, and the most disruptive in finished walls.
- The COPALUM method. Short copper pigtails are joined to the aluminum wire with a COPALUM crimp connector at every connection and splice, and the devices are connected to the copper.
- AlumiConn connectors. CPSC lists the AlumiConn connector as an acceptable alternative method for the same pigtail repair.
CPSC does not consider pigtailing with ordinary twist-on connectors a permanent repair, noting that substantial numbers overheated in testing. It calls CO/ALR-rated outlets and switches, at best, an incomplete repair. Both may be used as an emergency, temporary repair for one failed connection, with a complete repair to follow.
What this means for a dead outlet
In an aluminum-wired home, a dead outlet or a warm switch is usually one connection that has failed. We can repair that connection properly the same way CPSC describes, and we will tell you how the rest of the house looks while we are there. Fixing only the connection that failed leaves the others on the same timeline, so the conversation that follows is usually about remediating the whole house, either with pigtails at every connection or with copper rewiring.
Insurance is often what starts that conversation. Citizens Property Insurance's 4-point inspection form asks the inspector whether branch circuit aluminum wiring is present, asks for details of any remediation, and has checkboxes for connections repaired with COPALUM crimps or AlumiConn connectors. Keep the paperwork from any remediation, because the next inspector will ask.
See electrical repairs, whole-home rewiring and electrical safety inspections for how we approach each, and our guide to how one bad connection kills several outlets for the mechanics.
Questions people ask
Is aluminum wiring illegal?
No. CPSC's guidance is about repairing its connections, not a ban on having it.
Can I just replace the outlets with ones rated for aluminum?
CPSC calls CO/ALR devices, at best, an incomplete repair, because they have failed in laboratory tests and do not cover every connection in the house.
Need it looked at?
KRW Electric (EC13012832) troubleshoots and repairs dead outlets and warm connections in aluminum-wired homes in Pinecrest, Coconut Grove, South Miami and Miami Beach, with same-day service when scheduling permits. Call (305) 359-7312 and tell us what you are seeing. We will ask a few questions, tell you whether it sounds urgent, and give you the earliest time we have. Our before you call checklist covers what to have ready, and what happens on a repair visit explains the rest.
Reviewed by Kyle White, KRW Electric Company LLC — licensed electrical contractor EC13012832.
