If an inspector or electrician has pointed at your panel and said the words "Federal Pacific" or "Zinsco," you've probably already sensed this isn't a normal old-panel conversation. Both brands show up on insurance blacklists and inspection reports for the same reason: a documented pattern of breakers that don't do their one job. Here's what the evidence actually says, and what it means for your house.
What's Actually Wrong With These Panels?
A circuit breaker's entire purpose is to trip — to cut power — when a circuit is overloaded or shorted. That's what prevents overheated wiring from starting a fire. The core defect in Federal Pacific Electric (FPE) "Stab-Lok" panels, made from the 1950s through the 1980s, is that a significant share of their breakers fail to trip when they should, according to testing summarized by InspectApedia. The U.S. Consumer Product Safety Commission investigated FPE panels starting in the early 1980s; independent lab testing referenced in that research found that roughly half of the Stab-Lok breakers evaluated didn't trip within rated limits. Zinsco panels (and the related GTE-Sylvania panels) have a related but distinct problem: their breaker contacts can fuse or melt to the bus bar during a fault, which can leave a breaker reading "off" while still energized, or unable to trip at all.
Neither defect is about the panel simply being old. A 1970s panel from a different manufacturer that's still functioning correctly is a different situation. This is a design and manufacturing issue specific to these product lines.
How Big Is the Risk, Really?
It's hard to get a precise national number, because most house fires aren't traced back to a specific panel brand after the fact. The most-cited estimate, from researcher Jesse Aronstein's field research (summarized on InspectApedia), puts FPE Stab-Lok-related failures at roughly 2,800 fires and 13 deaths per year, with an estimated 1-in-6,000 annual fire risk for a home with one of these panels installed. Treat that as a modeling estimate from advocacy-adjacent research, not a government statistic — but it's consistent with why the panels keep showing up on hazard lists decades after production stopped.
What isn't in dispute: no major panel manufacturer has been allowed to sell anything like these designs since electrical codes tightened. It's not illegal to keep an existing FPE or Zinsco panel in your home, but it is illegal for a licensed electrician to install a new one today — they don't meet current National Electrical Code testing standards.
Why Do Insurance Companies Care So Much?
This is where the issue becomes urgent for a lot of homeowners, even ones who've never had a problem with their panel. Federal Pacific and Zinsco panels show up on the same "ineligible risk" lists insurers use for aluminum branch wiring and knob-and-tube. In practice, that means:
- Some insurers decline to write a new homeowners policy at all until the panel is replaced.
- Others will renew an existing policy but flag it at the next inspection or underwriting review.
- A few major carriers have been non-renewing policies specifically because of these panel brands in certain markets.
If you're buying, selling, or refinancing a home with one of these panels, expect it to come up during the inspection and possibly hold up your insurance binder. Sellers increasingly replace the panel before listing just to keep the transaction from stalling.
How Much Does It Cost to Replace One?
Costs vary by region, panel amperage, and whether the electrician also needs to update grounding, add a subpanel, or bring the service up to current code while they're in there. Published cost guides give a general sense of the range:
| Scope | Typical Cost Range |
|---|---|
| Standard panel replacement (any brand, 100–200A) | $1,300–$4,500 |
| Federal Pacific or Zinsco full swap-out | $2,000–$4,500, higher in some markets |
| Panel plus meter/service upgrade | $3,000–$10,000+ |
Figures pulled from Angi's electrical panel cost data and a 2026 cost breakdown by panel type. Local labor rates, permit fees, and how hard the panel is to access all move the number. For a sense of hourly rates in your area, see our guide on electrician cost per hour.
A few homeowners try to defer the cost by just monitoring the panel or having an electrician "service" individual breakers. Most licensed electricians won't do partial repairs on these panels — replacement breakers for discontinued FPE and Zinsco lines are hard to source and don't fix the underlying design issue, so the standard recommendation is a full panel swap.
Is a Tripping Breaker a Different Problem?
If your panel is tripping breakers frequently, that's a separate (and more common) issue than the FPE/Zinsco defect — most tripping is caused by circuit overload or a specific faulty appliance, not a bad panel brand. We cover the usual causes in why do my circuit breakers keep tripping. The FPE/Zinsco concern is closer to the opposite problem: breakers that fail to trip when they genuinely should.
What to Do About It
Start by confirming the brand. Open the panel door and check the label — "Federal Pacific Electric," "FPE," "Stab-Lok," "Zinsco," or "GTE-Sylvania" are the names to look for. If you're not comfortable opening the panel yourself, a home inspector or electrician can confirm it in a few minutes.
If you have one of these panels, get it evaluated by a licensed electrician rather than relying on how the house has performed so far — a panel that's caused no visible problems can still have breakers that won't trip in an actual overload, and you generally won't know until it matters. Ask your insurance agent directly whether your current carrier flags these panels, since that timeline (not just the electrical risk) often decides how soon the replacement needs to happen.
Because pricing swings so much by market and scope, get quotes from more than one licensed electrician before committing. A second or third quote is really the only way to know whether a bid reflects a fair local price or not — otherwise you're just trusting the first number you hear.