If your home still has one of these panels, upgrading is one of the most important electrical safety improvements you can make.

Why Zinsco Panels Are Being Replaced

Zinsco electrical panels were manufactured primarily from the 1950s through the early 1970s and later sold under the GTE-Sylvania brand after the company was acquired.

While these panels were once common in residential construction, decades of field experience revealed serious issues with the design.

Known Problems With Zinsco Panels

Breakers can fuse to the bus bar

One of the most dangerous problems with Zinsco panels is that breakers can melt and fuse to the internal bus bar. When this happens, the breaker may appear normal but cannot trip during an overload.

Breakers may appear OFF but still conduct power

In some cases, a Zinsco breaker can be switched to the OFF position while electricity continues to flow through the circuit. This creates serious shock hazards for anyone servicing the system.

Aluminum bus bars corrode and overheat

Many Zinsco panels used aluminum bus bars which are prone to corrosion and increased electrical resistance. This resistance generates heat and can lead to arcing and electrical fires.

Because of these design issues, Zinsco panels are widely regarded by electricians as obsolete and unsafe.

Why Federal Pacific (FPE) Panels Are Being Replaced

Federal Pacific Electric Stab-Lok panels were also widely installed in homes built between 1950 and 1985, including many neighborhoods throughout the Puget Sound region.

The controversy surrounding FPE panels began in the late 1970s when investigations revealed serious problems with breaker reliability.

Known Problems With Federal Pacific Panels

Breakers may fail to trip during overloads

Independent testing has shown that many Stab-Lok breakers do not trip when they should, allowing wires to overheat during dangerous conditions.

Breakers can remain energized even when switched off

Some breakers have been documented to continue conducting electricity while in the OFF position, creating hazards during maintenance or repairs.

Certification concerns

Investigations in the late 1970s revealed that some Federal Pacific breakers did not meet Underwriters Laboratories (UL) standards despite being labeled as UL-listed.

Because of these issues, many electricians and inspectors recommend complete replacement of FPE panels rather than attempting repairs.

Real Fire Risks Associated With These Panels

Electrical panels are designed to act as the primary safety device for your entire electrical system. When breakers fail to trip properly, wiring can overheat until insulation melts or combusts.

Investigators and safety professionals have linked Federal Pacific panels to thousands of electrical fires annually, and both Zinsco and FPE systems are frequently cited in home inspection reports as major safety concerns.

In many cases, homeowners only discover the problem after opening the panel and finding melted bus bars, burned breakers, or fused components.

Signs You May Have a Dangerous Electrical Panel

Homeowners should watch for these warning signs:

• Flickering lights• Breakers that will not stay reset• Warm or buzzing electrical panels• Burning smell near the panel• Breakers that feel loose or stuck

However, many of the most dangerous failures cannot be seen without opening the panel, which should only be done by a licensed electrician.

Benefits of Replacing an Outdated Electrical Panel

Upgrading your electrical panel provides several important benefits:

Improved Safety

Modern breakers reliably trip during overloads, protecting your home from electrical fires.

Increased Electrical Capacity

Older homes were not designed for modern electrical demand such as:

• EV chargers• high-efficiency HVAC systems• modern appliances• home offices and technology

A new panel ensures your home can safely support these loads.

Easier Home Sales

Real estate agents and home inspectors routinely flag Zinsco and FPE panels during home sales. Replacing them removes a major negotiation obstacle.

Insurance Approval

Some insurance providers may require replacement of obsolete electrical panels before issuing or renewing coverage.

Zinsco & Federal Pacific Panel Replacement in Snohomish, King, and Skagit Counties

At LeMaster Electric, our licensed electricians specialize in electrical panel upgrades and replacements for homes across the Puget Sound region.

We help homeowners replace outdated panels with modern, code-compliant electrical systems designed to safely power today’s homes.

Our panel upgrade services include:

• Zinsco panel replacement• Federal Pacific (FPE) panel replacement• main service upgrades• electrical capacity upgrades• permitting and inspections• code-compliant installations

Schedule a Panel Inspection

If you live in Snohomish County, King County, or Skagit County and your home still has a Zinsco or Federal Pacific electrical panel, it may be time for an upgrade.

A professional inspection can determine whether your electrical system is safe, reliable, and capable of supporting modern electrical demand.

Contact LeMaster Electric today to schedule a panel evaluation or request a quote for an electrical panel upgrade.

Large portions of the Puget Sound region experienced rapid residential growth during the 1960s and 1970s. Many homes built during this period still contain their original electrical panels.

Communities where these panels are frequently found include:

Snohomish County

Everett, Marysville, Lake Stevens, Arlington, Monroe, Bothell, Edmonds

King County

Seattle, Bellevue, Redmond, Kirkland, Shoreline, Kenmore

Skagit County

Mount Vernon, Burlington, Anacortes, Sedro-Woolley

If your home was built before 1985, it is worth checking whether your electrical panel is a Zinsco or Federal Pacific model.