A heat pump is one of the largest continuous electrical loads most homes will ever add, and in Portland it usually lands on a house that was wired for gas heat. Sometimes the existing service handles it with room to spare. Sometimes it does not, and panel work becomes part of the project whether you planned for it or not. The only honest way to know which you are is a load calculation, not square footage and not a guess from the panel label.
Why so many Portland houses are switching
Two things are driving it. Summers here now come with stretches of real heat and smoke, and a heat pump is air conditioning that also heats the house, so one piece of equipment answers both problems. And a lot of the metro's gas furnaces are reaching the end of their lives at the same time, which is when people actually reconsider what to replace them with. Ductless mini-splits make it work in old houses with no ductwork at all.
What almost nobody plans for is the electrical side. The HVAC quote covers the equipment, not what happens if your panel has no room for the circuit it needs.
What a heat pump asks of your panel
A heat pump needs its own dedicated circuit, sized to the equipment's nameplate, plus a disconnect at the outdoor unit. That part is straightforward. The complication is what else is already spoken for on your service.
Most Portland homes built before the 1990s were fed 100 amps, which was plenty when heat, hot water, and cooking all ran on gas. Every appliance since moved to electricity eats into that number. If the house already has a Level 2 EV charger pulling 40 to 60 amps for hours at a stretch, or an electric range, or a heat-pump water heater, the heat pump may be the load that finally pushes past what the service can carry. Our guide to 100-amp versus 200-amp service covers where that line usually falls, including the 150-amp middle option that fits a lot of houses adding exactly one big load.
There is a second failure mode that has nothing to do with amperage: a panel that is physically full. No open breaker spaces, or nothing left but tandems, and there is nowhere to land the new circuit. Smaller problem than an undersized service, but still work that has to happen before the HVAC crew can finish.
The number that decides it is not on the equipment box
A load calculation adds up your home's real demand, including the new equipment, and compares it to what your service can actually deliver. It is why two houses on the same street with the same heat pump can get different answers. Do it before you sign the HVAC contract, not after: finding out mid-install that the panel cannot take the equipment is how a clean project turns into two trades waiting on each other and a permit nobody scheduled.
Panel upgrade or service upgrade
These get used interchangeably and they are not the same job. A panel upgrade replaces the breaker box inside the house, which is the fix when the service feeding you is already sized correctly and you have simply run out of room, or when the panel itself is outdated or unsafe. A service upgrade includes all of that plus the utility connection: the meter and meter base, the mast up your roofline, the heavy conductors, and the grounding. Going from 100-amp to 200-amp service is a service upgrade, and it needs coordination with PGE or Pacific Power, always carries a permit and inspection, and takes your power down while the work happens. Our page on panel upgrade versus service upgrade lays out which is which.
Timing differs too. A panel upgrade is often a one-day job; a service upgrade usually runs one to three days once utility and inspection scheduling are in the mix. If your panel is already showing its age, our guide on how to tell if a panel is outdated is the place to start, and for numbers, most upgrades in the metro land between $2,500 and $7,500 as covered in our Portland panel upgrade cost guide.
Where the incentive money actually lands
This trips people up constantly. Energy Trust of Oregon incentives reward the efficient equipment, not the wiring that makes it possible. So the heat pump can carry an incentive while the panel work generally does not, even though the panel work is what let the heat pump go in at all. Do not plan a budget around a rebate on the panel itself. Programs open, pause, and change terms on their own schedules, so check current availability before you count on any figure. Our Oregon rebates and incentives page gives the honest rundown on each program we get asked about.
If an EV is also on the list
Plenty of households add both within a year or two of each other, and doing the electrical work once is cheaper than doing it twice. If that is you, size the service for both now rather than for whichever arrives first. Whether a charger needs a panel upgrade walks through how that decision gets made.
When to call an electrician
Call before the HVAC install is scheduled, not during it. Call if your panel is full, if the main breaker still reads 100 amps and you plan to electrify further, or if breakers already trip under the loads you run today, because that is the house telling you it is out of headroom before you add anything.
For planned work like a panel or service upgrade, ballpark quotes by phone or photo are free, and we will tell you honestly if your existing service is fine as-is. For repair calls, our $95 service visit covers dispatch and a visual assessment by a licensed electrician. Either way, get in touch and we will run the load calculation before anyone quotes you a number.