How to Troubleshoot Your Business’s Antiquated Knob-and-Tube Wiring

What is Knob-and-Tube Wiring?

Knob-and-tube wiring was commonly installed in homes and buildings in the early 1900s. It features:

This antiquated wiring can be a fire and shock hazard if damaged or overloaded. Proper troubleshooting and repairs are crucial.

Dangers of Faulty Knob-and-Tube Wiring

Faulty knob-and-tube wiring poses serious risks, including:

Any defects in old wiring should be promptly repaired or replaced. The hazards only get worse over time.

How to Troubleshoot Knob-and-Tube Wiring

Carefully inspecting and testing your business's antique wiring is crucial for spotting potential hazards. Follow these troubleshooting steps:

Visual Inspection

Circuit Testing

Wiring Condition

Load Evaluation

Prioritizing Repairs and Replacement

The extent of remediation needed depends on the severity of damage found during troubleshooting:

Focus on hazardous areas first:

Replacing the oldest, most deteriorated wiring takes priority over moderately maintained systems.

Repairing vs Replacing Knob-and-Tube Wiring

Targeted repairs can serve as stopgap measures to improve safety temporarily while you save up for rewiring projects. But full replacement should be the long term goal for fuse boxes, wiring and devices.

Hiring a Licensed Electrical Contractor

Due to the expertise required, it is advisable to have a professional electrician conduct knob-and-tube inspections, repairs or replacement.

When hiring a contractor:

Avoid attempts at DIY repairs, which can put you at further risk. The cost of an electrician is well worth it for your safety.

Is Your Antiquated Wiring an Emergency?

Certain red flag situations constitute an urgent electrical emergency:

In an emergency, shut off power at the main breaker and call an electrician immediately. Otherwise, schedule repairs as soon as reasonably possible.


While antiquated knob-and-tube wiring does not meet modern safety standards, hazards can be minimized by thorough troubleshooting and appropriate repairs by a qualified electrician. Replacement provides maximum safety. Stay vigilant for any signs of faulty wiring in older businesses.