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Knob and Tube Wiring

Knob and Tube is a wiring method that was used in homes in the early 1900s to 1940s and is no longer used.

These older electrical systems do not have the same safety benefits as modern ones. For example, ground fault circuit interrupters make wet locations like bathrooms and outdoor locations safer.

It may surprise you that many insurers will not provide or renew coverage on homes with this type of wiring. They consider it to be a higher risk. Some insurers may make you replace the knob and tube wiring before they provide coverage.

If your home has knob and tube wiring, ESA recommends hiring a Licensed Electrical Contractor (LEC) to do an assessment of your home’s electrical system. This is different than a home inspection because it only focuses on the electrical. The LEC can check the knob and tube conductors for signs of deterioration or damage. They may recommend replacing the wiring to ensure your safety.

Facts about knob and tube wiring:

  • Knob and tube wiring is safe, provided it is properly maintained by a Licensed Electrical Contractor.
  • Even though the latest Ontario Electrical Safety Code (OESC) 28th Edition 2021 has deleted the installation rules of knob and tube wiring, the OESC is not retroactive.