Two brands of electrical panel — Federal Pacific Electric (FPE) "Stab-Lok" and Zinsco (also sold as GTE-Sylvania) — installed heavily from the 1950s through the early 1980s. The long-standing concern, raised by home inspectors and electricians, is that some of their breakers can fail to trip on an overload or short circuit, which defeats a breaker's one safety job.
$2,000–4,000 to replace the panel (more if the service is upgraded too)Address before purchaseElectrical
Why it matters
A breaker that doesn't trip is a potential fire risk. Independent testing of FPE Stab-Lok breakers for the U.S. Consumer Product Safety Commission found a large share failed to trip under UL test conditions. Importantly, the CPSC closed its investigation in 1983 — citing insufficient budget — without making a formal determination that the breakers are defective, and the panels were never recalled. So the honest framing is: these are widely regarded by inspectors and many insurers as failure-prone and worth replacing, not subject to a government recall. Because the failure mode is hidden ("it's worked for years" is exactly how it looks right up until it doesn't), they're typically flagged for replacement rather than re-testing.
How to spot it
FPE: the "Federal Pacific Electric" or "Stab-Lok" name on the panel or breakers, often with a red strip across the breaker handles. Zinsco: "Zinsco" or "GTE-Sylvania" labels and colourful (red/blue/green) breaker handles. A photo of the panel label and breaker faces is usually enough to identify the brand.
What it costs
About $2,000–4,000 to replace the panel; more if the electrical service is upgraded (e.g. 60A to 100/200A) at the same time, which is common in older homes.
What to do
Address before purchase. Have a licensed electrician confirm the brand and condition and quote a replacement, and factor it into your offer. Some insurer questionnaires ask about these panels, so check coverage before removing conditions.
Education and triage, not a home inspection. Casaroo identifies the panel brand from a label photo — a licensed electrician confirms the panel and replaces it. We flag the brand; we don't certify any individual breaker.
Common questions
What is Federal Pacific & Zinsco electrical panels?
Two brands of electrical panel — Federal Pacific Electric (FPE) "Stab-Lok" and Zinsco (also sold as GTE-Sylvania) — installed heavily from the 1950s through the early 1980s. The long-standing concern, raised by home inspectors and electricians, is that some of their breakers can fail to trip on an overload or short circuit, which defeats a breaker's one safety job.
Why does it matter for home buyers?
A breaker that doesn't trip is a potential fire risk. Independent testing of FPE Stab-Lok breakers for the U.S. Consumer Product Safety Commission found a large share failed to trip under UL test conditions. Importantly, the CPSC closed its investigation in 1983 — citing insufficient budget — without making a formal determination that the breakers are defective, and the panels were never recalled. So the honest framing is: these are widely regarded by inspectors and many insurers as failure-prone and worth replacing, not subject to a government recall. Because the failure mode is hidden ("it's worked for years" is exactly how it looks right up until it doesn't), they're typically flagged for replacement rather than re-testing.
How can I spot it?
FPE: the "Federal Pacific Electric" or "Stab-Lok" name on the panel or breakers, often with a red strip across the breaker handles. Zinsco: "Zinsco" or "GTE-Sylvania" labels and colourful (red/blue/green) breaker handles. A photo of the panel label and breaker faces is usually enough to identify the brand.
How much does it cost to fix?
About $2,000–4,000 to replace the panel; more if the electrical service is upgraded (e.g. 60A to 100/200A) at the same time, which is common in older homes.
A licensed electrician confirms; Casaroo flags, it does not inspect.
Last reviewed 2026-06-27.
Casaroo reviews each guide against current pricing, code, and insurer practice. Cost ranges are 2026
estimates that vary by region, size, and access — confirm specifics with a licensed professional.