Expert Electrical Contractor Thomas Reilly Explains Knob-and-Tube Wiring Risks in HelloNation

AMHERST, N.H., Nov. 1, 2026 /PRNewswire/ -- The article examines aging electrical systems, modern power demands, and why inspection matters for homeowners and buyers.

KEY HIGHLIGHTS

• Knob-and-tube wiring lacks grounding and may have deteriorated insulation or unsafe modifications.
• Insulation surrounding active wires can trap heat, interfering with the system's original design.
• A licensed electrician can identify active wiring, assess its condition, and help plan replacement.

Is knob-and-tube wiring safe in an older home? HelloNation has published a HelloNation article that provides the answer through insights from Thomas Reilly, Expert Electrical Contractor of Amherst, New Hampshire, explaining how aging wiring can affect safety, insurance, and renovation plans.

How Does This Older Wiring System Work?

The HelloNation article explains that knob-and-tube wiring was commonly installed from about the 1880s through the 1940s. Ceramic knobs supported separate wires, while ceramic tubes protected them where they passed through wood framing.

The system used rubber and cloth insulation and relied on surrounding air to release heat. Although appropriate for its era, the design predates today's electrical demands and grounding needs.

The article notes that these systems lack a ground wire. Aging insulation can also crack or fall away, leaving exposed conductors that create shock or fire risks.

Why Can Modern Household Changes Create Problems?

The article describes how high electrical demand can overload older circuits. Air conditioners, microwaves, and other appliances may place demands on wiring beyond its original purpose.

Adding insulation around active wires can trap heat. The article also identifies improper splices and oversized replacement fuses as concerns that may compromise safety.

Visible ceramic components can help identify the system in unfinished spaces. However, the article cautions that two-prong outlets alone do not confirm its presence, and an electrician must determine which wiring remains active.

What Should Homeowners Consider Before Renovating?

The HelloNation article explains that active knob-and-tube wiring may complicate insurance coverage or a home sale. Requirements vary, with some insurers seeking an inspection or replacement.

The article describes replacement as installing modern grounded cable throughout affected areas. Accessibility, layout, and wall materials influence the work, and some homeowners complete rewiring in stages.

Until replacement, the article advises avoiding overloaded circuits, keeping visible wiring clear of insulation and storage, and leaving repairs to qualified professionals.

What Is Knob-and-Tube Wiring and Is It Safe Today? features insights from Thomas Reilly, Expert Electrical Contractor of Amherst, New Hampshire, in HelloNation.

FREQUENTLY ASKED QUESTIONS

Does Older Wiring Always Present an Immediate Danger?

According to Thomas Reilly, Expert Electrical Contractor of Amherst, New Hampshire, undisturbed wiring in good condition may continue working when not overloaded. Its condition still warrants professional evaluation.

Can Insulation Cover Active Wires?

Thomas Reilly, Expert Electrical Contractor of Amherst, New Hampshire, explains in the article that surrounding insulation can prevent heat from escaping. The system was designed to operate with open air around its wires.

Does Rewiring Require Opening Every Wall?

Based on insights from Thomas Reilly, Expert Electrical Contractor of Amherst, New Hampshire, electricians can often fish new cables through walls. The extent of access needed depends on the home's construction and layout.

About HelloNation

HelloNation is America's Good News Network, a premier media platform built on the idea that good news travels faster when real people tell real stories. Through its community-focused publications and innovative "edvertising" approach, HelloNation delivers content that informs, inspires, and spotlights the leaders making a meaningful impact in their communities.

SOURCE HelloNation