Do You Need a 200 Amp Panel Upgrade? A California Homeowner's Guide

Your electrical panel is the one component in the house that every other electrical thing depends on. It is also the one nobody looks at until something goes wrong.

Here is how to work out whether yours needs attention, and how to avoid being sold an upgrade you do not need.

What amperage actually means

The amperage rating is the maximum current your service can deliver at once. It is not a measure of how much electricity you use over a month, it is a ceiling on simultaneous demand.

• 60 amp — obsolete. Common in homes wired before 1960. Cannot support modern living.
• 100 amp — adequate for a smaller home with gas heat, gas cooking and gas water heating. Tight the moment you electrify anything.
• 125–150 amp — a middle ground that is often enough, and sometimes the cheaper right answer.
• 200 amp — the modern standard for a family home, and effectively required if you are adding an EV charger plus electric heating or cooking.
• 400 amp — large homes, ADUs on the same service, workshops, or multiple EVs.

The honest answer on whether you need 200 amps

You need a load calculation, not a rule of thumb. A load calculation adds up your square footage, fixed appliances, heating and cooling equipment and vehicle charging, then applies demand factors that account for the fact you never run everything at once.

We do this before recommending anything. It is common for us to tell a homeowner in a modest house with gas appliances that their 100 amp service is genuinely fine, and that their real problem is a full panel that needs a sub panel rather than a whole service change. That is a much smaller job.

Equally, if you are planning EV charger installation, a heat pump, an induction range or a hot tub, upgrading once now is far cheaper than upgrading twice.

Signs your panel is failing, not just full

These are not "keep an eye on it" items. They mean call an emergency electrician:

• Warmth on the panel cover or on individual breakers
• A buzzing, humming or crackling sound from inside
• Any burning smell, even faint, even intermittent
• Rust or water staining inside the enclosure
• Scorch marks, pitting or discolouration on the bus bars
• Breakers that trip well below their rated load
• Breakers that feel loose or will not seat firmly

Panels that should be replaced regardless

Federal Pacific Stab-Lok. Widely installed from the 1950s to the 1980s. Independent testing has repeatedly found breakers that fail to trip under fault conditions. There is no repair.

Zinsco and Sylvania-Zinsco. The aluminium bus is prone to corrosion and heat damage where breakers clip on. Breakers can appear off while still passing current.

Challenger. Similar failure patterns, particularly overheating at the breaker connection.

Fuse boxes. Not inherently unsafe, but a screw-in fuse can be replaced with an oversized one by anyone, which defeats the protection entirely. Capacity is also far below what a modern home draws.

What a panel upgrade involves

A full service change is a bigger job than swapping a box. It typically includes a new meter main, new service entrance conductors, a new grounding and bonding system, the new panel with circuits transferred and correctly labelled, a permit, an inspection and a scheduled utility disconnect and reconnect.

Most residential upgrades are a single day on site with power off for part of it. The scheduling constraint is usually the utility rather than us, which is why we book that in advance.

Do not skip the surge protector

While the panel is open, adding a panel-mounted whole-home surge protective device costs a fraction of what it would cost on its own visit. Given what a modern home contains in electronics, heat pumps and appliance control boards, it is the cheapest insurance available.

If your panel is showing any of the warning signs above, or you are planning to add load, call (833) 652-8933. We run the load calculation first and tell you honestly what you need. Learn more about panel upgrades and breaker box replacement.