Understanding Knob and Tube Wiring

Knob and Tube Wiring

Table of Contents

If you have an older home with original wiring, you may be wondering if your home has knob and tube wiring, and how this electrical system differs from modern home electrical wiring. For homeowners using a modern electrical load, it’s important to know that your home needs to have a modern, upgraded electrical system.

At Fusion Electric, we offer high-quality, modern, licensed electrical work to homeowners and businesses across the Kansas City area. In this guide, we’ll discuss what knob and tube wiring are, and why it’s important to upgrade your home to a modern electrical system.

What Is Knob and Tube Wiring?

Knob and tube wiring was a common form of wiring a home or building in the US from the early 1900s up until the 1950s. This electrical system comprises two copper wires, one hot and one neutral, that run through porcelain knobs and tubes. The wires are usually covered in an insulative material to protect from electrocution should someone come into contact with the live wire. These systems can typically handle up to 60 amps of power.

Considered innovative for its time, this outdated wiring system is no longer considered safe or compatible with a modern home or business’s electrical demand. The wiring method also poses shock and fire hazards that modern wiring systems do not. If you have knob and tube wiring, read on to learn why it’s best to hire a reputable electrical to upgrade your electrical system as soon as possible.

Why Knob and Tube Wiring Is Incompatible with Modern Electrical Demand

Knob and tube wiring is no longer compatible with modern electrical load or safety standards due to its maximum amp capacity, ungrounded system, and risk of deterioration from age.

Incompatible with a Modern Power Load

While this form of electrical wiring may have been able to meet and handle the common electrical load of its time, knob and tube wiring simply can not handle the power demand of a modern household or business. Modern homes commonly put out at least 150 amps of power daily, which is over twice the maximum load this old system of wiring can handle.

This means, for example, a home built in the 1930s with original wiring, will greatly struggle to support the electrical demands of modern appliances that may be in the home. This can lead to constant circuit breaker tripping, blown fuses in older homes, and even poses a risk of fire.

Ungrounded System

This old type of wiring only has two copper wires- the live wire and the neutral wire. There is no grounded wire in this system, which means that excess electricity does not have a ground wire to safely travel back into the ground. Rather, you are at risk of being electrocuted should your person present the path of least resistance for the excess energy to travel through.

Risk of Deterioration from Age

Knob and tube wiring phased out as the common means of wiring buildings in the 1940s/1950s. This means that if your home still has this kind of electrical system, you’re looking at having a system that is at least 70 years old. The insulation very well may have deteriorated at this point, leaving dangerously exposed wires, posing shock and fire risk. You also may have a system that has been tampered with over the last century in which previous homeowners may have attempted their repairs or alterations themselves.

The Bottom Line? Replace Your Knob and Tube Wiring with a Modern Electrical System

If you have this old type of wiring in your home, the best thing you can do is have the entire electrical system replaced as soon as possible. This may sound like a daunting and expensive task, but it’s certainly worth making sure you protect your home and loved ones from shock and fire hazards.

A new system will not only be safer but will perform far better and more efficiently, saving you money and preventing power surges and circuit breaker tripping.

Call in the Pros at Fusion Electric

At Fusion Electric, we’re proud to offer top-of-the-line electrical services to home and business owners across the Kansas City area. If your house has knob and tube wiring, contact us today about upgrading to a modern, vastly safer, and more efficient electrical system.

Jeff LeSuer avatar

Jeff LeSuer




home safety inspection

*Applies to labor only. Must mention coupon at time of service. All repairs and installations require a trip charge of $89. Not valid with other offers.


off any residential service or repair

*Applies to labor only. Must mention coupon at time of service. All repairs and installations require a trip charge of $89. Not valid with other offers.


off panel upgrades

*Applies to labor only. Must mention coupon at time of service. All repairs and installations require a trip charge of $89. Not valid with other offers.

Get Fast, Affordable Electrical
Repair With The Service You Deserve

Same-day Service Available