Get $300 in Free Electrical Work for Your Home or Business

Knob and Tube Wiring Replacement

If an inspection, remodel, or insurance review turned up knob and tube wiring, Coy Electric can evaluate what's still active and replace it with modern, grounded circuits. Licensed, bonded, and insured, with upfront written pricing and permits handled.

Fully licensed, bonded & insured — CCB #9388

Call (971) 306-8484

80+ Five-Star Reviews

17,000+ Projects

Completed in Oregon

A+ BBB Rated

Better Business Bureau

Why Choose Coy Electric for Knob and Tube Wiring Replacement?

Old-Home Experience

52 years working on Portland-area homes with plaster, balloon framing, and original wiring.

Written Scope & Pricing

You get a clear written estimate before any work begins — no surprises.

Permits & Inspections

We pull the applicable permits and coordinate inspections on your behalf.

Clean, Code-Compliant Work

Grounded circuits installed to current code, with careful patching and cleanup.

Knob and Tube Wiring Replacement for Older Homes

Knob and tube wiring replacement is one of the most common projects we take on in older housing stock. Knob-and-tube was the standard residential wiring method from the late 1800s into the 1940s: separate hot and neutral conductors run through the framing, supported by ceramic knobs and passed through porcelain tubes, insulated with cloth and rubber, and installed without a grounding conductor. It was well engineered for the era — and the era expected a few lights, not the electrical load of a modern household.

Most homeowners don't go looking for this wiring. They find it. A home inspection flags active circuits during a purchase, an insulation contractor stops work in the attic, a remodel opens a wall, or an insurance review asks a direct question. At that point the useful next step isn't panic — it's a professional evaluation that establishes how much old house electrical wiring is still energized, what condition it's in, and what replacing it would actually involve.

Coy Electric has been serving homeowners across our service area for 52 years. We're woman-owned and family-run, licensed, bonded, and insured under Oregon CCB #9388, and we give every customer an upfront written estimate before work begins.

Signs Your Home May Have Knob-and-Tube Wiring

Ceramic knobs or porcelain tubes visible in the attic, basement, or crawl space
Two-prong, ungrounded outlets throughout part or all of the house
Cloth-covered wiring instead of modern plastic-jacketed cable
A home inspection report that identifies active knob-and-tube circuits
Older circuits spliced into or mixed with newer wiring
Flickering lights, warm outlets or switch plates, or breakers that trip repeatedly — these have many possible causes, so treat them as a reason to investigate rather than a diagnosis

Seeing ceramic knobs doesn't automatically mean you have a live problem — plenty of homes have long-dead runs still stapled to the joists. Testing is what separates an abandoned relic from an active circuit feeding your bedrooms.

Why Homeowners Replace Knob-and-Tube Wiring

Knob-and-tube is not automatically dangerous because it's old. The concerns are specific and worth understanding:

No equipment-grounding conductor

Knob-and-tube predates grounding, so there's no safe path for fault current and no true ground for computers, appliances, or surge protection.

Aging or damaged insulation

Cloth and rubber insulation becomes brittle over decades, especially near heat sources, light fixtures, and areas disturbed by rodents or storage.

Decades of unsafe alterations

Most problems we find aren't original workmanship — they're later extensions, taped splices, and buried junction points added by non-electricians.

Modern electrical demand

These circuits were designed for a few lights and a radio, not kitchens, home offices, HVAC, and everything plugged in today.

Renovation and insulation projects

Attic insulation, finished basements, and remodels frequently force the issue, since covering these conductors raises legitimate heat concerns.

Home sales and insurance reviews

Buyers, lenders, and carriers often ask about it. Requirements vary by company, so confirm specifics with your own carrier or agent.

Our Knob-and-Tube Evaluation and Replacement Process

1
Evaluate accessible wiring and the panel
We inspect attics, basements, and crawl spaces where wiring is reachable and assess the service panel's condition and capacity.
2
Determine which circuits are still active
We test and trace conductors to separate live knob-and-tube circuits from abandoned runs that were simply left in place.
3
Explain partial vs. complete replacement
We walk you through the realistic options for your home rather than defaulting to the largest possible project.
4
Provide a written scope and estimate
You get the work, materials, access points, and price in writing before anything begins.
5
Handle permits and inspections
We pull the applicable electrical permits and coordinate the inspection with your jurisdiction.
6
Install modern, grounded wiring
New cable is routed through accessible pathways, with grounded devices, proper junction boxes, and minimal disruption to finished surfaces.
7
Test, verify, and walk you through it
We test each completed circuit, label the panel, clean up, and explain exactly what was replaced and what remains.

Partial Replacement vs. Whole-Home Rewiring

Not every house with knob-and-tube needs a complete rewire. The right scope depends on how many active circuits remain, how accessible they are, the condition of the conductors, your renovation plans, the capacity of your panel, and any requirements attached to a sale, permit, or insurance conversation.

Partial rewiring makes sense when a small number of legacy circuits are still live and the rest of the home has already been modernized — a common situation in houses updated piecemeal over the decades. It's targeted, less disruptive, and often the honest recommendation.

Whole-home rewiring becomes the better value when active knob-and-tube runs throughout the house, when walls are already open for a remodel, or when so many circuits need attention that replacing them one at a time costs more in labor than doing it once. We'll show you the tradeoff instead of assuming it.

What Affects the Cost?

We don't publish a price range for this work, because two homes on the same street can differ by a wide margin. These are the factors that actually move the number:

Size and layout of the home, including number of stories
How much knob-and-tube wiring is actually still active
Access through attics, basements, crawl spaces, plaster, and finished walls
Number of circuits, switches, fixtures, and receptacles involved
Panel capacity and whether panel work is required
Permits and inspections for your jurisdiction
Whether the work is completed all at once or phased over time

After the evaluation you get a written scope and price. A home electrical safety inspection is a good starting point if you want the full picture of your wiring, grounding, and panel capacity before deciding.

Request a Free Estimate

Getting Electrical Work Done Has Never Been Easier

Simple, transparent, and hassle-free from start to finish.

Request Your Free Estimate

Fill out the form or call us. We'll get back to you the same day during business hours.

Get Upfront, Honest Pricing

A licensed electrician evaluates your project and walks you through the pricing before we start. No pressure, no surprises.

We Get It Done Right

Our experienced electricians complete the work, clean up, and make sure everything is up to code.

Call (971) 306-8484

See What Our Customers Are Saying

Real reviews from our local community.

"Fantastic company with great electricians. All-star staff of professionals like Jarred, Kelsey, and Micah. They get the job done quickly, correctly, and at a reasonable price. Equally important, they are kind and easy to work with. Highly recommend"

Dave A.

"Well, I think Wyatt has saved me from having a house fire! That's how important competent electricians are. Prompt, courteous & thorough. Did a great job cleaning the site afterward. Will certainly contract with Coy Electric in the future."

Marcia T.

"I had a great experience with this local electric company. They were prompt, showed up right on time, and the customer service was excellent from start to finish. They came to my mom's house and replaced some lighting, and everything was done efficiently and professionally. Super easy to work with and very reliable — I'd definitely recommend them!"

Cali B.

Read all 80+ reviews on Google →

Frequently Asked Questions

What is knob-and-tube wiring?

Knob-and-tube is an early wiring method used from roughly the 1880s through the 1940s. Individual hot and neutral conductors run separately through ceramic knobs and tubes, insulated with cloth and rubber rather than modern plastic, and with no equipment-grounding conductor.

Is knob-and-tube wiring always unsafe?

No. Age alone does not make it hazardous, and some original installations are still intact. The concerns usually come from what happened afterward: deteriorated insulation, decades of amateur splices and extensions, higher modern loads, buried junctions, and insulation packed around conductors that were designed to shed heat into open air. That's why an evaluation matters more than an assumption.

How can I tell whether it is still active?

Visible ceramic knobs in an attic or crawl space don't necessarily mean the circuit is live — many homes have abandoned runs left in place. An electrician can test the conductors and trace them back to the panel to determine which knob-and-tube circuits are still energized and what they feed.

Do I need to replace all of it?

Not always. Some homes only have a few active legacy circuits that can be replaced individually; others have enough active wiring that a whole-home rewire is the more sensible path. We give you both options with pricing where both are reasonable.

Can knob-and-tube wiring be replaced without removing every wall?

In most homes, yes. We fish new cable through attics, basements, crawl spaces, and wall cavities, opening small access points where needed rather than removing finished surfaces wholesale. Homes with no attic or basement access and solid plaster require more openings, and we'll tell you that upfront.

Will I need an electrical panel upgrade?

Sometimes. Homes with knob-and-tube often still have a small or fuse-based service that lacks capacity or available spaces for new grounded circuits. We assess the panel during the evaluation and tell you whether a panel upgrade is required or simply recommended.

Does knob-and-tube wiring affect homeowners insurance?

It can. Some carriers ask about it, some price differently, and some decline coverage — practices vary by company and change over time. We don't speak for insurers; confirm requirements directly with your carrier, and we can provide documentation of the work we complete.

Can insulation be installed around knob-and-tube wiring?

Knob-and-tube conductors were designed to dissipate heat into open air, so surrounding them with insulation raises real concerns and is restricted in many situations. If you're planning an attic insulation project, have the wiring evaluated first — this is one of the most common reasons homeowners call us.

How long does replacement take?

It depends on scope. Replacing a handful of active circuits is typically much shorter than a full rewire, which is a multi-day to multi-week project depending on home size and access. You'll get a schedule expectation with your written estimate.

Do permits and inspections apply?

Yes — replacing branch circuits and panel work is permitted electrical work in Oregon and Washington jurisdictions. We handle the applicable permits and coordinate the inspection so your finished work is documented and code-compliant.

How much does knob-and-tube replacement cost?

There's no honest flat number, because the amount of active wiring, home size, access, circuit count, and panel condition drive the price. We evaluate the home and give you a written estimate before any work starts. Call (971) 306-8484 to schedule.