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Panel Upgrade Decision Guide
Upgrade from 100A to 200A when an NEC load calculation shows your planned loads exceed safe capacity — most commonly when an EV charger and a heat pump land on the same older panel. Upgrade regardless of capacity when the panel is a safety-class problem: a fuse box, a recalled brand like Federal Pacific or Zinsco, or a corroded bus. And before committing to bigger service, check whether smart load management could defer the upgrade entirely — sometimes it can.
What are the warning signs of a failing electrical panel?
Carbon Dust, Heat Transfer & Corrosion
Three warning signs of failing connections inside your electrical panel
CARBON DUST
HEAT TRANSFER
CORROSION
Any one of these found inside a panel means connections are failing — and it never gets better on its own
What It Means — and What We Do
It Only Gets Worse
Arcing pits metal, heat loosens lugs, and corrosion spreads — damage accelerates.
Everyday Symptoms
Flickering lights, warm breakers, and nuisance trips often trace back here.
Panel Inspection
We open, inspect, and check every connection to catch damage early.
Clean & Re-Terminate
Damaged breakers replaced; connections cleaned, torqued to spec, and re-tested.
Replace When It's Time
Widespread damage or an obsolete panel? We'll give you an honest call.
Panels should be opened by a licensed electrician — if yours hasn’t been checked in years, a panel inspection is the safe way to know what’s inside.
Related: Panel upgrade decision guide Panel upgrade services
Quick answer
Upgrade from 100A to 200A when an NEC load calculation shows your planned loads exceed safe capacity — most commonly when an EV charger and a heat pump land on the same older panel. Upgrade regardless of capacity when the panel is a safety-class problem: a fuse box, a recalled brand like Federal Pacific or Zinsco, or a corroded bus. And before committing to bigger service, check whether smart load management could defer the upgrade entirely — sometimes it can.
- The trigger is arithmetic, not vibes: an NEC 220 load calculation of your existing plus planned loads decides whether 100A is actually full.
- A typical Puget Sound 100A→200A panel upgrade runs $8,000–$16,000 installed, including code corrections and utility coordination.
- WA HEAR can contribute up to $4,000 toward a panel upgrade (plus up to $2,500 for wiring) when it enables electrification, for income-eligible households.
- Fuse boxes and recalled panels (Federal Pacific, Zinsco) are replacement decisions at any capacity — insurers increasingly force the issue.
- Adding just an EV charger? Load management or a smart panel sometimes avoids the upgrade — run the calc before buying bigger wire.
Use this guide when
An EV charger or heat pump quote came back with 'panel upgrade required,' your breakers trip when the dryer and oven run together, your home still has a fuse box or a 100A panel from the 1970s, or your insurer flagged the panel brand at renewal. Schedule the assessment before equipment delivery — a panel discovered full on install day delays the whole project by weeks of permit and utility lead time.
What actually drives the decision
Two independent questions. Capacity: does an NEC 220 load calculation of your real loads — existing plus the EV, heat pump, or induction range you're planning — exceed what 100A safely delivers? Safety: is the panel itself trustworthy hardware? A load calc can save you from an unnecessary upgrade; no calculation rescues a Federal Pacific panel.
Compare your options
The 200A upgrade
The standard fix for electrifying homes: new load center and main breaker, service-entrance work as needed, grounding and bonding brought to current code, utility coordination, permit, and inspection. It resets capacity for decades — an EV today, a heat pump next year, induction after that — and it's the default recommendation when the load calc says you're genuinely out of room.
The smart panel / load-management alternative
SPAN-style smart panels and simpler load-management devices (like an EV circuit splitter) can pace flexible loads so total demand stays inside your existing service — NEC provisions recognize managed loads in the calculation. When the driver is one big flexible load, this can defer the utility service upgrade and its lead time entirely. See our SPAN vs traditional panel comparison for the full tradeoff.
The safety-driven replacement
Fuse boxes, Federal Pacific (FPE Stab-Lok), Zinsco, and heat-damaged or corroded panels get replaced for reliability, not capacity — these are the panels with documented failure-to-trip histories, and insurers increasingly surcharge or decline them. Capacity can stay at 100A where the load calc supports it; often the sensible move is doing the 200A upgrade in the same visit since labor overlaps heavily.
What does each option cost installed in the Seattle area?
Ranges below match our published Puget Sound electrical panel cost guide. Panel quotes vary more than most trades because the panel is only part of the job — service condition, grounding, and code corrections ride along, and every jurisdiction inspects the work.
| Option | Typical installed range | What that covers |
|---|---|---|
| Panel replacement (same capacity) | $4,000–$9,000 | Like-for-like load center swap — e.g. retiring a fuse box or recalled panel — with grounding/bonding corrections, permit, and inspection. |
| 100A → 200A service upgrade | $8,000–$16,000 | New load center, main breaker, service-entrance work, utility coordination, code corrections, permit, and inspection. Relocation or meter & mast work is its own $10,000–$20,000 scope. |
What changes the price
- Rebates: WA HEAR contributes up to $4,000 toward a panel upgrade and up to $2,500 toward wiring when the work enables electrification (income-eligible households).
- Service entrance condition: replacing the mast, meter base, or service conductors adds scope — and utility lead time.
- Code ride-alongs: grounding electrodes, bonding, AFCI/GFCI protection, and working clearance fixes get folded into any honest panel quote.
- Utility queue: PSE and Seattle City Light coordination timelines vary by season and jurisdiction — plan weeks, not days, for service changes.
- Circuit count and condition: relocating, labeling, and repairing circuits during the swap moves the number inside the range.
Ranges are representative Seattle / Puget Sound installed prices, not a quote — your home's specifics set the real number. Eco gives you an upfront price before any work begins.
Key terms and context
This guide is written for electrical decisions in the Puget Sound. It uses the same terminology you'll hear from inspectors, technicians, and permit offices.
Overloading a 100A panel instead of deciding
The warning signs of a panel running at its edge — a main breaker that trips under combined loads, warm breaker faces, flickering when big appliances start — are also fire-risk signs. Riding an overloaded panel while you defer the decision is the one option with no upside: it stresses the bus, trips at the worst times, and hands the timing to the panel instead of you.
Buying capacity when the problem was management
The mirror mistake: paying for a full service upgrade — with utility fees and weeks of lead time — when the only new load is an EV charger that load management could pace inside existing capacity. A proper NEC 220 calculation with managed-load provisions costs nothing to run and can save thousands. Demand the calc before signing either way.
The unpermitted panel swap
Panel work without a permit and inspection is a problem that surfaces at the worst moments: home sale, insurance claim, or the next electrician's visit. Every legitimate Puget Sound panel quote includes permit and inspection — a bid that omits them isn't cheaper, it's incomplete.
How we build this guidance
- Every recommendation starts with an NEC 220 load calculation of your actual loads — we'll show you the math that says upgrade or don't.
- We quote both paths where load management could defer the upgrade — Eco installs conventional panels and SPAN smart panels.
- Rebate screening (WA HEAR panel and wiring funds) is part of the estimate, not an afterthought.
Methodology: Capacity decisions per NEC 220 load calculations including managed-load provisions; safety classifications per documented panel recall and failure histories. Install ranges align with Eco's published Puget Sound panel cost guide; rebate figures per 2026 WA HEAR program rules.
Last updated: 2026-07-05
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Common questions
Will PSE or Seattle City Light upgrade my service, or does Eco?
Both, in sequence. The utility owns the service drop and meter; Eco handles everything on your side — panel, service entrance, grounding, permits — and coordinates the utility's disconnect/reconnect and any service-drop upgrade. That coordination is built into our quotes, and the utility queue is usually the longest lead-time item.
Do I automatically need 200A for an EV charger?
No — and this is where load calculations earn their keep. Many 100A homes can host a Level 2 charger by right-sizing the circuit (a 32A charger instead of 48A) or adding load management that pauses charging while big appliances run. If you're also adding a heat pump or induction range, though, the combined math usually does point to 200A.
How do I know if my panel is one of the recalled or problem brands?
Open the panel door and read the label: Federal Pacific (Stab-Lok breakers) and Zinsco are the two with documented failure-to-trip histories that inspectors and insurers flag. If you see either — or a fuse box — have it assessed regardless of how well it seems to work. 'It's never given me trouble' is exactly how failure-to-trip problems present.
How long does a panel upgrade take and will I lose power?
The panel work itself is typically one day, with power off for most of that working day. The full project — load calc, permit, utility scheduling, install, inspection — usually spans a few weeks depending on the jurisdiction and utility queue. That's why we say assess before your EV or heat pump is delivered, not after.
What rebates apply to panel upgrades in Washington?
WA HEAR can put up to $4,000 toward a panel upgrade and up to $2,500 toward wiring for income-eligible households (≤150% of area median income) when the work enables electrification — a heat pump, heat pump water heater, or EV charging. It's a point-of-sale discount, and we confirm eligibility and handle the paperwork at the estimate.
Questions? Talk to a real pro.
Licensed, insured, and bonded across the Puget Sound — upfront pricing before work begins.