Should all Zinsco panels be replaced?

Yes, all Zinsco panels, also known as Zinsco Sylvania or GTE Sylvania panels, should be replaced as soon as possible according to most licensed electricians, home inspectors, and electrical safety experts, regardless of whether they appear to be working. Zinsco panels were installed in millions of homes from the 1950s to the 1980s and have well-documented design flaws including aluminum bus bars that corrode and overheat, circuit breakers that can weld or fuse to the bus bars and fail to trip during overloads or short circuits, breakers that appear to be off while still energized, and poor overall construction that allows arcing. Independent testing has shown that Zinsco breakers fail to trip at a high rate, creating serious fire hazards where wires can overheat and start fires inside walls. While there was no formal recall by the Consumer Product Safety Commission, the company went out of business and many models lost UL listing. Insurance companies often refuse to insure homes with Zinsco panels or require replacement, and home inspectors routinely flag them during real estate transactions. The recommended replacement is a modern panel from Square D QO or Homeline, Eaton BR or CH, or Siemens installed by a licensed electrician for 1,500 to 4,000 dollars, which is a worthwhile investment for safety.