Fuses protect a circuit just as well as breakers when the right fuse is used. The problems with old fuse boxes come from age, limited capacity and how easy it is to put in the wrong fuse.
Are fuse boxes dangerous?
A fuse box is not dangerous just because it uses fuses. The risks are:
- Oversized fuses. Screw-in (Edison base) fuses of different sizes fit the same socket. Putting a 30-amp fuse on a circuit wired for 15 amps removes the protection and lets the wire overheat. Type S adapters prevent this.
- Age and wear. Many fuse panels are 60 or more years old, with worn contacts, loose connections or heat damage.
- Small capacity. Many fuse services are 60 amps or less, which is not enough for modern kitchens, EV charging or heat pumps.
- Often paired with older wiring such as knob-and-tube or ungrounded circuits.
Will my insurance cover a house with a fuse box?
Insurers set their own rules. Some ask about fuse panels, knob-and-tube or problem panel brands, and some require an electrician's inspection or replacement. Ask your insurer directly; an electrical inspection report can help.
What does replacing a fuse box involve?
Usually it means a new breaker panel and, because fuse services are often small, a service upgrade to 100 or 200 amps with a new meter-main, permit, utility disconnect and reconnect, and inspection. The electrician also checks the existing wiring, because older wiring may need repairs before it is connected to a new panel.
How much does it cost?
It depends on whether the service also needs upgrading. For reference, IES's 200-amp service upgrade starts at $6,500 and a same-location 200-amp main panel replacement starts at $4,675.
About these prices: rough starting-at prices from the IES price book. The final price depends on what we find on site, your utility and your city or county. Estimates are free.
Common questions
Is it illegal to have a fuse box in California?
No. Existing fuse panels are generally allowed to stay in use. Replacement is usually driven by safety, capacity, insurance or a remodel that requires it.
Can I put a bigger fuse in if it keeps blowing?
No. A fuse that keeps blowing means the circuit is overloaded or has a fault. A bigger fuse removes the protection and can let the wiring overheat and start a fire.
General information for California homes under the California Electrical Code (based on the NEC). Local rules and inspectors can vary. Not a substitute for an on-site inspection. Never work inside a panel, at the meter or on live circuits.