Zinsco and Sylvania-Zinsco panels were installed widely across Southern California from the 1950s to the 1970s, and they are still common in San Fernando Valley ranch houses and hillside homes from that era. Their breakers can fuse to the aluminum bus bar and fail to trip, and many home inspectors flag them.
Electrification is the biggest driver of panel work in LA: heat pumps, induction cooking, EV chargers and rooftop solar often all land on a panel that dates to the original build. Fuse panels and Zinsco equipment are still found in older neighborhoods.
Zinsco and Sylvania-Zinsco panels were widely installed in San Diego homes from the 1950s to the 1970s, and they are still found in Clairemont, Serra Mesa, Allied Gardens and other mid-century neighborhoods. Their breakers can overheat and fuse to the bus, and inspectors routinely flag them.
Rooftop solar is very common, and adding solar, a battery, an EV charger or a heat pump to an original 60 or 100 amp panel often requires an upgrade. Coastal homes see corrosion on outdoor equipment from salt air.
San Jose's 1950s and 1960s tract neighborhoods, including much of Willow Glen, Cambrian and the east side, were built when Zinsco and Sylvania-Zinsco panels were common, and many are still in use. Their breakers can overheat and fuse to the bus, and Bay Area home inspectors flag them routinely.
Tract homes often have 100 amp services that cannot carry an EV charger, a heat pump and an induction range together. Eichlers, with post-and-beam construction, exposed ceilings and radiant floor heat, leave little hidden space to run new wiring.
Fresno's postwar neighborhoods, from Fig Garden to the older parts of the Sunnyside and Hoover areas, were built when Zinsco and Sylvania-Zinsco panels were widely used, and many remain. Their breakers can overheat and fuse to the bus, a real concern when AC runs through summers above 100 degrees.
Older homes often have 60 or 100 amp services that were sized before central air, and adding a larger AC system, rooftop solar or an EV charger frequently requires an upgrade. Rooftop solar is common across the city.
Bakersfield's postwar neighborhoods, including much of the Oleander-Sunset area, College Heights and the subdivisions that spread south and west in the 1950s through the 1970s, were built when Zinsco and Sylvania-Zinsco panels were common, and many remain. Their breakers can overheat and fuse to the bus, a concern in a city where air conditioners run through months of 100-degree days.
Older homes often have small services sized long before central air, and adding a larger AC system, solar or an EV charger frequently requires an upgrade. Rooftop solar is common in newer subdivisions.
Long Beach's postwar neighborhoods in Lakewood Village, Los Altos and the Plaza area were built when Zinsco and Sylvania-Zinsco panels were common, and many are still in use. Their breakers can overheat and fuse to the bus, and inspectors routinely flag them.
Many older homes still have 60 or 100 amp services, and adding an EV charger, heat pump or solar often needs an upgrade. Homes near the water see corrosion on meters, outdoor panels and exterior outlets.
Oakland's postwar homes in the hills and in neighborhoods such as Maxwell Park and Millsmont were built when Zinsco and Sylvania-Zinsco panels were common, and many still have them. Their breakers can overheat and fuse to the bus, and inspectors routinely flag them.
Older flatland homes often have knob-and-tube and small services, while hill homes face wildfire-season power shutoffs. Heat pumps, induction cooking and EV chargers often require a service upgrade.
Lincoln Village and the postwar neighborhoods north of downtown Stockton were built when Zinsco and Sylvania-Zinsco panels were common, and many of these homes still have them. Breakers that can overheat and fuse to the bus are a particular concern in a city where air conditioners run hard through months of triple-digit heat.
Older homes near downtown may have knob-and-tube or small services, while mid-century tracts often have panels electricians suggest replacing. Heat drives heavy AC loads, and rooftop solar is common.
West Anaheim filled with tract homes in the 1950s and 1960s, the same years Zinsco and Sylvania-Zinsco panels were going into Southern California houses by the thousands, and many of those panels are still on exterior walls today. The concern is breakers that overheat and fuse to the aluminum bus, so they may not trip.
Many tract homes have original panels and wiring now 60 or more years old, and some have aluminum branch wiring. Owners adding solar, batteries, heat pumps and EV chargers often need more capacity.
