Summary:

• Insurance companies in California are starting to crack down on homes that still have Knob & Tube (K&T) wiring. Failing to upgrade could put your insurance at risk.
• Many insurers feel older K&T electrical systems are a fire risk, even though there are yet to be any documented incidents in the Bay Area.
• K&T wiring isn’t designed to handle modern power loads, which may cause it to overheat, spark, or start a fire. Upgrading will resolve this issue.
• The best time to replace your knob & tube wiring is now! New wiring may help you unlock support for advanced technologies, like EV chargers and solar panels.

People who own older homes in the Bay Area are once again fighting to keep their insurance policies—but climate isn’t the cause. Insurers are reportedly canceling or refusing to renew policies on houses with outdated knob and tube (K&T) wiring, citing fire risks as the reason.

Those affected by the purge have only two options: upgrade to a newer electrical system, or apply for coverage under California’s costly and controversial FAIR Plan instead. So, what’s really going on, here—and what can you do about it?

Caccia Home Services is here to help. Below, we’ll explain why K&T is so risky, and how testing your electrical system can help you avoid the potential dangers that come with it.

What Is Knob & Tube Wiring?

K&T wiring is a very old, outdated electrical system you’ll typically find in heritage properties and houses built before the 1950s. Back then, when electricians wired a building, they would run the wires through ceramic tubes held in place by porcelain knobs.

K&T was the industry standard by around 1880. Power loads were still very low, and it was capable of handling outlets and lights up to 60 Watts, which was more than sufficient at the time. It was also very cost-effective and relatively easy to install.

However, this system rapidly fell out of favor after the turn of the century as the demand for power increased and the limitations of K&T became clear. By the 1940s, it was pretty much obsolete—but many owners are unaware that it can be problematic, or even unaware that their homes have it at all.

Why Are Insurance Companies Cancelling Policies for Homes with K&T Wiring?

There aren’t any documented cases of K&T wiring causing house fires in San Francisco, but that doesn’t matter to insurers. They see it as a fire risk, and if they suspect you have it in your home, you could be at risk of losing your policy.

It doesn’t matter if you’ve had it inspected, vow to avoid high-wattage appliances, or follow every safety best practice in the book. If K&T is present, your insurance company wants it gone.

Related: Is Your Old Electrical Panel Putting Your Insurance at Risk?

Risks & Challenges of Knob & Tube Wiring

The biggest concern with K&T wiring is age. The older any electrical system gets, the more likely it is to degrade and develop problems like these:

• Deteriorating Insulation: The insulative coating on wiring may degrade over time, crack, split, or flake off. Exposed wires greatly raise your risk of a fire.
• Overloading Issues: K&T just wasn’t designed to handle modern electrical loads. If you try to power outlets and fixtures over 60 watts, the wires will overheat.
• No Proper Grounding: Unless they’ve been upgraded, most K&T systems don’t have any ground wires. This greatly raises the risk of shocks and fires.
• Illegal DIYs: Electricians find unsafe upgrades and illegal modifications in older K&T systems all the time. These can also raise your risk of shocks and fire.

It was also relatively common for electricians to leave some K&T circuits when working on a home or upgrading. That’s important because it means you still may have it in your walls, even if you can’t see it.

Related: Electrical Panel Upgrades & Repairs | Get A Free Quote

When & Why to Replace Knob & Tube Wiring

The best time to replace your K&T wiring was yesterday. The second-best time to upgrade is now! Upgrading gives you peace of mind—and more practical benefits, too:

• Selling your home? K&T wiring reduces the market value and deters buyers. A recent electrical system upgrade is one of the best ways to boost value instead.
• Having insurance issues? If your insurer flags your home, they’ll often give you a chance to upgrade before canceling your policy. It might lower your premiums, too!
• Noticing failures? If your lights are flickering, you’re tripping breakers, or you keep losing power, rewiring your home and adding a new panel might help.
• Need better protection? Modern electrical systems are much less likely to overload, overheat, or start fires. They help protect your home and everyone in it.

There’s just no substitute for knowing your wiring is safe and up to code.

Related: 10 Essential Upgrades for Older Homes

The Process of Replacing Knob & Tube Wiring

Upgrading the wiring throughout your home might feel overwhelming, but you won’t be on your own for this one. Our team at Caccia Home Services has your back, every step of the way.

• Step 1: Inspection & Evaluation: A licensed electrician will assess your existing wiring and recommend an upgrade plan.
• Step 2: Planning & Permitting: Upgrading your wiring requires pulling permits and ensuring compliance with local building codes.
• Step 3: Rewiring & Modernizing: New, grounded wiring (Romex) is installed and tested to ensure it meets current safety standards.
• Step 4: Final Inspection & Insurance Update: After the job is done, we’ll give you proof so you can update your insurance provider right away.

Call (650) 294-8504 to schedule your assessment. Ask us how we can help you step even further into the future with EV chargers and high-efficiency panels, when you call!

Trust Caccia Home Services to Help

Our team of licensed electricians can provide safe, efficient wiring replacements for homes with knob & tube wiring in the Bay Area. We have experience handling everything from inspections to full rewiring projects, so you can trust us to keep all work up to code.

Need help with plumbing, water heater issues, or your drain and sewer? We have licensed plumbers standing by to serve you with all of these issues and more, too.

As a family-owned and operated company here in San Mateo County, we’re committed to transparency and providing quality services at honest rates. Every customer gets an up-front estimate before we start the work, so there are no hidden fees or surprises. 

But don’t just take our word for it—take a look at our awards and reviews to see why your neighbors continue to rely on us for all of their plumbing and electric needs.

Don’t Wait Until It’s Too Late!

Replacing outdated wiring not only improves safety but also helps maintain your property value and insurability. If you still have K&T wiring in your home, don’t wait until your provider cancels your policy to take action—let us know right away so we can help.

Book an appointment for your wiring assessment to get the process started. Or, Call Caccia Home Services at (650) 294-8504 to chat about your options.