Older homes and property · independent publisher, not a contractor
Panel upgrades for a heat pump in Los Angeles
A heat pump needs a panel upgrade only when a load calculation shows the existing service cannot carry it. In LADWP territory, a new panel starts with a free LADWP meter spot request (online for homes up to 320 amps); LADBS inspects services up to 200 amps for LADWP, and meter work generally follows within 10 working days. Published LA prices put the upgrade at $2,000–$7,500.
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When a heat pump needs more panel
The contractor or an electrician adds the heat pump, air handler and any backup heat to the house's existing loads and compares the total with the service size. An AC-to-heat-pump swap often reuses the AC circuit. Replacing a gas furnace with an electric air handler adds new load. No rule of thumb replaces that calculation.
Ask before you accept a panel line
Ask for the load calculation behind it. A quote that adds a panel without one may be padded; a quote that skips the check may trip breakers in August.
The two ways the code lets you calculate
The National Electrical Code, adopted in California through the electrical code, gives two methods for adding load to an existing house. An LBNL summary sets them out:
| Method | How it works | Good for |
|---|---|---|
| NEC 220.83 (bottom-up) | 8,000 watts plus 40 percent of the remaining connected loads, plus the larger of heating or cooling when HVAC is added | Any house; needs a survey of appliances and circuits |
| NEC 220.87 (measured) | The highest measured demand over a year, times 1.25, plus the new load at nameplate | Houses with a year of utility interval data, or a 30-day recording |
The two methods can give different answers on the same house. The measured method often shows more room than the nameplate survey suggests, because real homes rarely run everything at once. Ask LADWP or your electrician whether a year of interval data exists for the house, which makes a 220.87 calculation possible, before you pay for a bigger service.
As a scale check, a 100-amp service at 240 volts is 24 kW. A 3-ton heat pump draws a fraction of that; the backup heat strip and any EV charger are usually the loads that tip the sum.
LBNL (Iain Walker), Avoiding Electric Panel and Service Upgrades, read 2026-10-26. Confirm methods against the code edition LADBS enforces.
Ways around a full upgrade
Researchers at Lawrence Berkeley National Laboratory list several ways homes electrify without a bigger service. Not all suit every house, and each still needs a permit and a licensed electrician.
Use less power per appliance
- Heat pump sized by a proper load calculation, not oversized
- Smaller backup heat strip, or none where the climate allows
- 120-volt appliances: LBNL lists 120V mini-splits, heat pump water heaters and washer-dryers
Share or manage circuits
- A smart circuit splitter lets two 240V loads share one circuit, one at a time
- Load managers throttle an EV charger to the power available
- A smart panel can shed loads by priority
These are design choices, not workarounds
Any of these must be shown on the electrical permit and pass inspection. Ask the contractor which one they would use and why, and get it in writing.
100, 125 or 200 amps?
Older LA houses often have smaller services than a modern 200-amp panel. Your main breaker or the meter base label shows the rating. A 200-amp service gives room for a heat pump, an EV charger and electric cooking together, but it is not automatically required for a heat pump alone. LADWP handles single-family services up to 320 amps through its online meter spot request, which covers the common 200-amp upgrade.
LADWP steps for a new or upgraded panel
- Request a meter spot. For single-family homes up to 320 amps this is online and free; an LADWP Electric Service Representative sets the panel location (LADWP, verify).
- Electrical permit from LADBS. LADWP says LADBS requires an electrical permit before an inspector can go to the jobsite.
- Inspection. For services up to 200 amps single phase, the LADBS inspector provides the final inspection for LADWP.
- Meter set. If no other LADWP work is needed, meter installation generally occurs within 10 working days.
LADWP Electric Services FAQs, read 2026-10-20.
Utility charges
LADWP says that when an upgrade uses existing service that can handle the new demand, "there are generally no installation charges involved". Charges may apply for conduit in public property, transformer work, distribution line work or street resurfacing (LADWP).
What LA contractors publish
The spread is wide because the job is. Swapping a panel in place is a different job from relocating the meter, trenching or replacing an overhead service drop.
Outside LADWP
Burbank, Pasadena and Glendale run their own electric utilities, and SCE serves most other cities, each with its own service process. Find yours in which utility serves my property.
Sources
- Lawrence Berkeley National Laboratory (Iain Walker), "Avoiding Electric Panel and Service Upgrades in Home Decarbonization" (2023) (retrieved 2026-10-26)
- LADWP, "Electric Services FAQs" (retrieved 2026-10-20)
- LADWP, "Request a Meter Spot for Single Family Residential Home or ADU up to 320 Amps" (official search result) (retrieved 2026-10-20) — verify before relying on it
- Reliable Heating and Air (Woodland Hills), AC installation cost in LA and Ventura County (retrieved 2026-09-29)
- Cold Cloud (Glendale), central air cost in Los Angeles (retrieved 2026-09-29)
- E & A Mechanical (Tujunga), heat pump installation cost in Los Angeles (retrieved 2026-09-29)
- HVACProjectCost.com, Los Angeles HVAC replacement cost (retrieved 2026-09-29)
Questions
Does every heat pump need a 200-amp panel?
No. It depends on the load calculation for the house. Many swaps reuse the AC circuit.
Can a heat pump work on a 100-amp panel?
Often, if the load calculation shows room. A right-sized heat pump with a small or no backup strip, or circuit sharing, can avoid an upgrade.
What is a 220.87 load calculation?
An NEC method that uses a year of measured peak demand, times 1.25, plus the new load. It needs utility interval data or a 30-day recording.
Does LADWP charge to upgrade my service?
Generally not when the existing service can carry the new demand; charges can apply for transformer, line or public-property work.
How long does LADWP take to set the meter?
Generally within 10 working days after inspection if no other LADWP work is needed.
Next step
Free quote request
Get a quote to check against these numbers
- Tell us about the job. Service, ZIP, property and timing. The form says right away if your ZIP is outside the area.
- We check the license first. Requests go only to contractors whose CSLB C-20 license we have matched on the state register. If none covers your ZIP yet, we email you and say so.
- Compare what comes back. Line the written quote up against the published ranges and the quote checklist.
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