Homes fitted with Aluminum wiring pose a safety risk to the owners of those houses.
Here is the outline of concern around aluminum wiring as written by the Electrical Safety Authority.
Aluminum wiring in residential installations
Issues with aluminum wiring
Since January of 2003 the Electrical Safety Authority has received an increasing number of questions
about the safety of aluminum wiring. In particular, purchasers or owners of homes built from the mid
1960’s until the late 1970’s with aluminum wiring are finding that many insurers will not provide or renew
insurance coverage on such properties unless the wiring is inspected and repaired or replaced as
necessary and this work is inspected by ESA and a copy of the certificate of inspection is provided to the
insurer. In some cases the insurer may require replacement of the aluminum wiring with copper wiring.
Check with your insurance company for their requirements.
Some homes may have a mixture of aluminum and copper wiring.
Reported problems with aluminum wiring have been related to the overheating and failure of aluminum
wiring terminations. This is due to aluminums tendency to oxidize and its incompatibility with devices
designed for use with copper wiring. Warm cover plates or discolouration of switches or receptacles,
flickering lights, or the smell of hot plastic insulation may evidence these problems.
Each home will be different and must be assessed on its own. It is highly recommended the homeowner
hire a licensed electrical contractor who is knowledgeable in the special techniques required for working
with and repairing aluminum wiring. The contractor should do an assessment, make the necessary
repairs, and have the work inspected by ESA. The homeowner should obtain a copy of the Certificate of
Inspection for their records and for their insurance company (if requested).
As mentioned above, where problems exist with aluminum wiring they are usually found at termination
points. This necessitates the opening of all outlets (receptacles, switches, fixtures, appliance connections,
and in the panelboard) and visually inspecting terminations for signs of failure and overheating without
removing or disturbing the devices or wiring. There should be no signs of overheating such as darkened
or discoloured connections, melted insulation, etc.
Where problems are found the damaged aluminum conductor should be cut back to remove the damaged
portion and then the necessary repairs made.
Required markings for devices used with aluminum wiring
Replacement receptacles and switches shall be installed in compliance with the Ontario Electrical Safety
Code and marked as per Table F1. (…see more here)