Zinsco and Federal Pacific panels: how to spot one and what to do

The quick check

Open the panel door. Look at the label, the breaker handles and the inside of the door.

• Federal Pacific Electric (FPE): the name FPE or Federal Pacific, and breakers marked Stab-Lok. Made mostly from about 1950 to 1980.
• Zinsco: the name Zinsco, Sylvania, GTE-Sylvania or Challenger. Millions were installed in the 1960s and 1970s. Some have colored breaker handles.

If either name shows, call a licensed electrician. Do not open the dead front yourself.

What the record says about Federal Pacific

The federal story is narrower than most web pages claim. In 1980 the parent company of FPE told the US Consumer Product Safety Commission that many FPE breakers did not fully meet UL requirements. The Commission tested them and confirmed failures of some calibration tests. In March 1983 it closed the investigation. It said the data did not establish a serious risk of injury, and it could not link the test failures to a hazard. It did not recall the breakers.

So the accurate statement is: the breakers failed some lab tests, and no federal order followed. That is why the advice comes from electricians and inspectors instead of a recall notice. The usual worry is a breaker that does not trip when a circuit overloads. A breaker that does not trip lets a wire run hot.

What is said about Zinsco

For Zinsco, the support is from trade and reference sources, not a federal finding. They describe breaker connections that loosen on the bus bar, which can cause arcing and heat, and breakers that fuse to the bus so they can neither trip nor be removed. Zinsco switched to an aluminum bus in the early 1960s. There is no recall or government safety notice for Zinsco, so electricians commonly replace them as a precaution.

Signs to act on now

Call an electrician soon, not at the next remodel, if you see:

• a burning smell, scorch marks or melted plastic near the panel,
• a breaker that does not reset or feels loose,
• lights that flicker with no clear cause, or a breaker that trips often (see breaker keeps tripping),
• a buzz or hot spot at the panel.

For a calm panel with no symptoms, replacement is still the common advice. It does not have to happen this week. A buyer’s inspection report might force the timing.

What replacement involves

Replacing one of these panels is the same work as any 200 amp panel upgrade, even when the new panel stays at the same size. The utility disconnects power, the electrician installs the new panel, the city inspects, and the utility reconnects. A permit is required. A new dwelling service panel also needs a surge protective device under section 230.67. See surge protection.

Because old panels hide old problems, expect the electrician to check:

• whether the existing wires reach the new panel or need an extension,
• whether any circuits are overloaded, undersized or double-lugged,
• whether the grounding and bonding meet current code,
• whether any aluminum branch wiring is present.

Cost

The typical SoCal range is $2,500 to $5,500 as of October 2026. It is the same as a regular panel swap at the low end. The high end covers damaged wiring or extra circuit work found when the old panel comes off. This is a desk estimate, not a published price list, so use the replacement cost page as a guide and compare written quotes.

Selling a home with one of these panels

Many home inspectors list both brands as a defect. A buyer might ask for replacement, a credit or a price cut. You can head that off by replacing the panel first and keeping the permit and inspection record. The home sale inspection guide lists the other electrical items that come up. Some insurers may also ask about these panels. Check with your own insurer, since policies differ.

What to ask

1. Is the panel a known problem brand, and which one?
2. Does the quote cover a new surge protective device, the permit and the utility steps?
3. What happens to the old wiring if it does not reach?
4. Who is responsible if the electrician finds more work behind the panel?