If you’re searching for this, you already have a heat pump or a furnace and AC and it’s dying, or dead, or old enough that you’re doing the math before it dies on its own schedule instead of yours. That’s a different question than “what does a first-time heat pump install cost,” and it deserves a different answer. Replacing existing equipment means dealing with what’s already in your walls: wiring that may or may not carry the new load, ductwork that may or may not need work, and an old unit that has to come out before anything new goes in. Here’s what that’s actually cost real homeowners across our Seattle service area this year.
How Much Does It Cost to Replace a Heat Pump in Seattle? The Real Range
The direct answer: heat pump replacement cost in Seattle has run from $7,608.62 to $22,888.07 across our own completed projects, and the number that matters for your home depends almost entirely on system size and scope, not luck or which contractor you happen to call.
| Homeowner | What Was Replaced | Final Cost | System Scale |
| Flynn, Ballard | Failed ductless AC → ductless heat pump, single zone | $7,608.62 | Smallest, lower end of the range |
| Anish, Seattle | Failed AC compressor → heat pump, bundled with water heater | $13,063.22 | Mid-size |
| Craig, Issaquah | 20-year-old furnace → full 5-ton heat pump system | $14,473.35 (after $10,400 rebate) | Large home, large rebate |
| Michael, Seattle | 16-year-old system → full ducted Mitsubishi heat pump | $22,888.07 | Largest, upper end of the range |
That’s roughly a $15,000 spread between the smallest and largest project on this list, and the difference tracks almost exactly with how much of the home’s existing system the new equipment needs to work with, and how large a space it needs to condition.
How Much Should a Heat Pump Replacement Actually Cost?
This is a different question than “what’s the range,” and it’s the one that actually protects you from overpaying. A fair price for heat pump replacement in Seattle should be built from a specific set of line items, not handed to you as one opaque number: the equipment itself, sized correctly for your home rather than just matched to what was there before; labor to remove and dispose of the old unit; installation and commissioning labor for the new one; any electrical work required if the new system’s circuit needs differ from the old one; and permitting.
If a quote can’t break down roughly what you’re paying for across those categories, that’s worth asking about directly. A fair price isn’t necessarily the lowest number. It’s a number you can actually see the shape of. The homeowners in our case history who ended up paying wildly different totals weren’t victims of inconsistent pricing. They had genuinely different scopes of work, and the price reflected that honestly.
Small Systems: Single-Zone Ductless Replacement Cost
The lower end of our documented range belongs to Flynn, in Ballard, whose ductless AC unit had failed entirely and whose first contractor offered only an unwarrantied repair with no mention of replacement at all. Flynn replaced the failed unit with a new Mitsubishi single-zone ductless heat pump: one outdoor unit, one indoor fan coil, covering a single room or open area rather than an entire home. The full replacement, including new line sets and installation, came to $7,608.62.
Single-zone ductless replacements are consistently the most affordable category in our case history, for a simple reason: the scope stays contained to one indoor-outdoor pair rather than a whole-home system, and there’s typically less electrical and ductwork complexity involved than a full ducted replacement.
Mid-Size Replacement: AC-to-Heat-Pump Upgrades
Anish’s project sits in the middle of the range. His AC compressor had shorted to ground (an internal electrical failure tripping his breaker every time the system tried to start) on a unit that was 17 years old and already out of warranty. Rather than repair a system with no remaining warranty protection, he replaced it with a Trane inverter heat pump, and bundled in a water heater replacement during the same visit. The combined project, after a $600 utility rebate and a $1,000 schedule discount, came to $13,063.22.
This case is a useful illustration of what affects the cost of heat pump replacement beyond just the equipment itself: bundling a second project into the same visit, as Anish did with his water heater, changes the total in ways that aren’t purely additive, shared crew time and scheduling incentives can bring the combined cost below what two entirely separate projects would run.
Full Ducted System Replacement Cost
The upper end of our range covers full ducted heat pump systems, and two cases show just how much scale and rebate structure can shift the final number even within this category.
Michael, in Seattle, replaced a heating-only system that turned out to be 16 years old, six years older than he’d assumed, with a full ducted Mitsubishi Hyper Heat system. His project priced out at $23,288.07 before incentives, and after a $400 Seattle City Light rebate, landed at $22,888.07, the highest final cost in our documented case history.
Craig, in Issaquah, replaced a 20-year-old non-functional furnace with a full 5-ton heat pump system for his 4,934-square-foot, 7-bedroom home, objectively the largest home and largest system in our dataset. His base price before incentives was actually the highest of any case at $24,873.35. But because his project qualified as a full fuel switch away from gas, it stacked three separate rebate programs worth $10,400 combined, bringing his final cost down to $14,473.35, lower than Michael’s smaller system, once rebates were factored in.
That comparison is the clearest evidence in this whole dataset that a bigger home doesn’t automatically mean a bigger final bill. Rebate eligibility can matter more than square footage.
The Fastest, Simplest Heat Pump Replacement: Like-for-Like Outdoor Unit Swap
There’s a fifth category worth naming separately, even without a dollar figure attached: a straight like-for-like outdoor unit swap, where a failed or aging outdoor heat pump unit is replaced with a new one using the same electrical circuit, the same line set routing, and the same indoor coil. In our Lake Stevens case, this exact scope was completed in a single 6-to-8-hour visit: no new electrical circuit, no ductwork changes, no additional trades to coordinate.
This is consistently the fastest and, by scope alone, the least expensive category of heat pump replacement available, because it avoids nearly every cost driver that pushes other projects higher: no new wiring, no permitting layers beyond the mechanical work itself, and no coordination between multiple crews. If your existing electrical infrastructure and ductwork are still compatible with a comparable replacement unit, this is the scenario worth asking your contractor about directly before assuming a full system overhaul is necessary.
What’s Included in Heat Pump Replacement Cost
Replacement cost covers more ground than installation cost alone, and it’s worth knowing what should be on that list before you compare quotes. Removal and responsible disposal of the old unit. Installation of the new outdoor unit and matched indoor coil or air handler. Any new electrical circuit or panel work required if the old wiring doesn’t support the new equipment’s load. Permitting (mechanical, and electrical or refrigeration work as applicable) handled and submitted on your behalf. System commissioning and testing to confirm proper operation before the crew leaves. And in cases where the old and new equipment aren’t a clean match, additional labor to adapt line sets, condensate drainage, or ductwork connections to the new unit.
This is the real difference between “install” and “replace” in practice: an install into new construction or a space with no prior equipment doesn’t carry the demo and disposal step, and it doesn’t carry the risk that existing infrastructure won’t match the new system’s requirements. Replacement does, every time.
Replacing Heat Pump vs Installing for the First Time: What’s Different
It’s worth being direct about this, because the two searches get treated as interchangeable when they’re not. Installing a heat pump for the first time (into new construction, or a home that’s never had one) starts from a blank slate: no old equipment to remove, no risk that existing wiring or ductwork was sized for a different system. Replacing a heat pump means working around what’s already there, which introduces variables an install project never has to deal with: is the existing electrical circuit adequate for the new unit, does the ductwork need modification, is the old equipment’s line set routing reusable or does it need to be redone.
If you’re comparing installed pricing more broadly, including for homes without existing equipment, our guide on what heat pump installation actually costs in Seattle covers that broader question. This article is specifically about the replace scenario, what it costs when there’s an old system coming out first.
Frequently Asked Questions: Heat Pump Replacement Cost in Seattle
How much does it cost to replace a heat pump in Seattle?
Based on our own completed replacement projects, costs have ranged from $7,608.62 for a single-zone ductless replacement up to $22,888.07 for a full ducted system replacement. The right number for your home depends primarily on system size and scope, whether you’re replacing one indoor-outdoor pair covering a single space, or a full ducted system serving an entire house, and whether the project qualifies for utility rebates that can meaningfully reduce the final cost.
How much should a heat pump replacement cost?
A fair price should reflect a clear breakdown of what you’re actually paying for: correctly sized equipment, removal and disposal of the old unit, installation and commissioning labor, any required electrical work, and permitting. Rather than comparing raw totals across quotes, ask each contractor to itemize these categories so you can evaluate whether the price matches the actual scope of your project, not just whether it’s the lowest number you received.
Does a single-zone replacement cost less than a full ducted system?
Yes, significantly. In our documented cases, a single-zone ductless replacement in Ballard came to $7,608.62, while a full ducted system replacement in Seattle came to $22,888.07, roughly three times the cost. The difference reflects the scale of equipment involved, the amount of ductwork or line set work required, and the number of indoor units being installed, not inconsistent pricing between similar projects.
Is $20,000 too much for a heat pump replacement?
Not necessarily, it depends entirely on the scope. A full ducted heat pump system replacement in our own case history came to $22,888.07 for a moderate-size Seattle home, which reflects the real cost of replacing an entire whole-home system rather than an inflated price. Where $20,000 would be worth questioning is on a smaller-scope project, like a single-zone or partial replacement, where our documented comparable costs have run well under half that amount.
Does replacing a heat pump cost more than a new AC?
It can be comparable or even lower once rebates are factored in, despite a heat pump technically doing more, providing both heating and cooling rather than cooling alone. In one of our cases, replacing an AC-only system with a heat pump add-on ended up cheaper than a standalone AC replacement would have been, once a local utility rebate applied specifically to the heat pump option. It’s worth pricing both directly rather than assuming AC-only is automatically the lower-cost path.
What’s included in heat pump replacement cost?
A complete replacement typically includes removal and disposal of the old unit, installation of the new outdoor and indoor equipment, any necessary electrical work to support the new system’s load, permitting for mechanical and electrical work as applicable, and full system commissioning and testing. This is meaningfully more than a first-time installation into a space with no existing equipment, since replacement also has to account for whether the home’s existing infrastructure is compatible with the new system.
Does heat pump replacement include removing the old unit?
Yes, removal and responsible disposal of the existing equipment is a standard part of a replacement project, not a separate add-on cost in most legitimate quotes. This is one of the clearest distinctions between a replacement project and a first-time installation, since new construction or a space that’s never had HVAC equipment doesn’t require this step at all. If a quote doesn’t clearly account for demo and disposal, it’s worth confirming that detail before work begins.
How fast can a heat pump be replaced like-for-like?
A straight like-for-like outdoor unit swap, using the same electrical circuit and line set routing as the old equipment, is the fastest replacement category we’ve documented, completed in a single 6-to-8-hour visit in one of our Lake Stevens cases. This timeline is only achievable when the existing electrical infrastructure and line set routing are still compatible with the replacement unit; projects requiring new circuits or ductwork changes take longer.
Key Takeaways for Seattle Homeowners Planning a Replacement
- Heat pump replacement cost in Seattle has run from $7,608.62 to $22,888.07 in our own documented projects, tracking closely with system size and scope rather than random market variation.
- A fair replacement price should be itemized (equipment, removal of old equipment, installation labor, electrical work if needed, and permitting), not delivered as a single unexplained number.
- Single-zone ductless replacements sit at the lower end of the cost range, while full ducted whole-home systems sit at the upper end, with roughly a three-times cost difference between them.
- A larger home doesn’t automatically mean a larger final bill: rebate eligibility, especially for full fuel-switch projects, can bring a large system’s final cost below a smaller project’s price.
- A like-for-like outdoor unit swap using existing electrical and line set infrastructure is both the fastest and typically the most affordable replacement category available.
- Replacing a heat pump is a meaningfully different project than installing one for the first time, since replacement always involves removing old equipment and confirming compatibility with existing wiring and ductwork.
The honest answer to “how much should this cost me” is never a single number pulled out of the air. It’s whatever your specific home’s existing equipment, wiring, and ductwork actually require, priced out line by line so you can see exactly what you’re paying for.
— Serge Nikolin, Co-Founder, Product Air Heating, Cooling and Electric
Marysville · Issaquah · Seattle · Western Washington