HVAC companies in Seattle, WA
Compare up to three local Seattle HVAC contractors from Henry's vetted bench — AC repair, furnace and heat pump service, and full system replacement.
Seattle's HVAC market has changed fast. A city that used to get by on a gas furnace and an open window now sees real summer heat, and after the 2021 and 2023 heat events, homeowners are done gambling on box fans. The catch is that most Seattle housing stock - Craftsman bungalows in Ballard and Wallingford, 1920s-1940s cottages in Beacon Hill and Rainier Valley, old apartment conversions near Green Lake - was built with no ductwork at all, or ducts sized only for a gravity or early forced-air furnace. That makes a straightforward AC add-on the exception rather than the rule. Most jobs here are ductless mini-split installs, ducted heat pump conversions replacing an aging oil or gas furnace, or duct modifications to make cooling actually work. Seattle City Light and Washington State also offer real money for heat pump conversions, which shifts a lot of replacement decisions away from simple furnace swaps. Henry's job is to hand you up to three licensed, L&I-registered Seattle HVAC contractors who pull the SDCI mechanical permit, size the equipment for your specific house, and quote in writing instead of guessing over the phone.
The Henry Standard
Every HVAC contractor in our network agrees to three things.
Show up
Call back. Keep appointments. And if something changes, communicate it.
Quote honestly
Equipment, scope, permit, and price in writing — so you know what you're agreeing to.
Finish the work
See the job through, pull the permit, and pass inspection before calling it finished.
Nothing revolutionary. Just the way we believe doing business should still be done.
How Henry matches you with Seattle HVAC contractors
- Step 1
Tell Henry what the system is doing
Your ZIP, whether it's a repair or a replacement, and how soon you need it handled. Two minutes, four questions.
- Step 2
Pros are already vetted
Only three Henry Standard HVAC contractors in your Seattle-area ZIP get your request — pros we've checked for responsiveness, references and written estimates.
- Step 3
Compare up to three quotes
You hear from three HVAC contractors at most — never a list of twenty — and every estimate comes in writing. You pick, or pick nobody.
What HVAC work costs in Seattle
| AC repair (minor: capacitor, contactor, fan motor) | $200 - $520 |
| AC repair (major: compressor or evaporator coil) | $1,500 - $3,600 |
| Furnace repair (igniter, sensor, control board) | $220 - $850 |
| Ductless mini-split (1 to 2 zones, no ducts) | $6,000 - $14,500 |
| Ducted heat pump conversion (replacing gas or oil furnace) | $12,500 - $24,000 |
| Full system replacement (AC + gas furnace) | $10,000 - $18,500 |
| Oil-to-gas or oil-to-heat-pump furnace conversion | $9,500 - $22,000 |
| Seasonal tune-up / maintenance visit | $110 - $250 |
Ranges are general estimates gathered from homeowner-reported quotes in the Seattle area, not an offer or a quote for your project.
When to schedule HVAC work in Seattle
Seattle's heating season runs roughly October through April and is generally mild, but the cooling season - short as it is - has turned serious. Multi-day heat events in late June through August now regularly push into the 90s, and the 2021 heat dome pushed the region past 100 degrees. Because so many Seattle homes are adding cooling for the first time rather than replacing an old unit, demand spikes hard whenever a heat warning is forecast, and installers book out for weeks. The best time to schedule a cooling install or heat pump conversion in Seattle is February through May, before the rush. Furnace and heating system work is best handled in late summer or early fall, ahead of the first cold, wet stretch that drives emergency heating calls.
Permits and HOA rules
Inside Seattle city limits, mechanical permits for new HVAC installations, system replacements, ductless mini-split installs, and ductwork changes are issued by the Seattle Department of Construction and Inspections (SDCI), filed through the city's online permitting portal, with an inspection required before the permit closes. Addresses outside city limits - unincorporated King County, Shoreline, Burien, Renton, and similar suburbs - permit through their own jurisdictions, so confirm which office covers your address before assuming SDCI applies. Heat pump conversions and oil-to-electric conversions frequently require a companion electrical permit for a new 240-volt circuit or a panel upgrade, and that permit is separate from the mechanical permit with its own inspection. Any contractor quoting a heat pump or mini-split job who cannot tell you exactly which SDCI permits apply and confirm they will pull them is not who you want handling a five-figure install.
Licensing and insurance in Washington
Washington requires HVAC/R contractors to be registered with the Department of Labor & Industries (L&I), and you can verify any company's registration, bond, and insurance status directly on the L&I contractor lookup before signing anything. L&I treats electrical work as a separate specialty license from HVAC/R contracting, so a heat pump conversion that requires new wiring or a panel upgrade needs an electrician with a Washington electrical license in addition to the HVAC/R contractor - one license does not cover both trades. Technicians handling refrigerant also need EPA Section 608 certification. Ask for the L&I registration number, look it up before you sign, and confirm both the HVAC/R and, if relevant, electrical work are covered by properly licensed people rather than one crew claiming to do it all.
Why Seattle HVAC jobs look different from most cities
The single biggest fact shaping HVAC work in Seattle is that a large share of the housing stock was never built with cooling in mind, and a lot of it was not built with modern ductwork either. Craftsman bungalows in Ballard and Wallingford, and cottages from the 1920s through 1940s in Beacon Hill and Rainier Valley, often relied on radiators, wall heaters, or early gravity furnaces with no ducts suitable for forced air at all.
That makes ductless mini-split systems the practical answer for a huge share of Seattle retrofits. One outdoor condenser can feed two to four indoor heads, covering the main living space and bedrooms without tearing open plaster walls or crawling through a tight, unconditioned crawl space to run new ductwork.
Homes that do have ductwork - many in West Seattle, Magnolia, and Green Lake - were usually ducted for heating only, with returns and supply runs sized for a furnace, not for cooling airflow. Adding a condenser to that system without evaluating duct sizing and static pressure produces a house that is loud in some rooms and never quite cool in others.
Older homes still running an oil furnace, common in parts of Queen Anne and Magnolia, are increasingly being converted straight to a ducted heat pump rather than replaced with another oil or gas unit, especially with Seattle City Light and state incentives making the switch more affordable.
How to vet and compare Seattle HVAC contractors
Start with the L&I registration number on any quote. Washington's L&I contractor lookup shows registration status, bond amount, and insurance in seconds, and it filters out unregistered crews that show up after a heat wave hits the news.
If the job involves new wiring, a subpanel, or a 240-volt circuit for a heat pump or mini-split, confirm separately that an electrician holding a Washington electrical license is doing that portion. An HVAC/R registration does not authorize electrical work, and a contractor who says otherwise is cutting a corner.
Read the quote for completeness: equipment make, model, and heating/cooling capacity; whether a Manual J load calculation was actually performed for your house; the SDCI mechanical permit; the electrical permit if new wiring is involved; the scope of any duct work; and parts and labor warranties listed separately.
Ask directly what happens to your existing ductwork on a cooling retrofit, or whether the recommendation is ductless. In a 1930s Beacon Hill or Wallingford house, the honest answer is often 'ductless is simpler and works better here' - a contractor who just wants to sell a central AC add-on onto undersized ducts is optimizing for the sale, not your comfort.
What HVAC work costs in Seattle
Seattle labor rates run above the national average and above many other West Coast metros outside the Bay Area. Minor AC repairs - capacitors, contactors, fan motors - run $200 to $520, while major failures like a compressor or evaporator coil run $1,500 to $3,600.
Ductless mini-split installs for homes with no existing ducts run $6,000 to $14,500 for one to two zones, and scale up from there with each additional indoor head. A ducted heat pump conversion, replacing an aging gas or oil furnace with a heat pump and matched air handler, runs $12,500 to $24,000 before incentives.
A conventional full system replacement pairing a new AC and gas furnace runs $10,000 to $18,500. Oil-to-gas or oil-to-heat-pump conversions - which involve decommissioning an oil tank in addition to the new equipment - run $9,500 to $22,000 depending on tank removal and any electrical panel work required.
These are planning ranges based on homeowner-reported Seattle quotes. Crawl space access, electrical panel capacity, duct condition, and whether an old oil tank needs professional decommissioning are the variables that move real bids the most.
Permits, incentives, and electrical work before you sign
SDCI issues the mechanical permit for HVAC installs, replacements, and duct modifications inside Seattle city limits, and an inspection is required to close it out. Outside the city, King County or the relevant suburban jurisdiction handles it - confirm which office covers your address.
Heat pump conversions and mini-split installs commonly need a new 240-volt circuit, and older Seattle homes on 100-amp electrical service sometimes need a panel upgrade before the heat pump and any backup heat strips can be installed safely. That is a separate electrical permit, performed by a licensed electrician, and it belongs on the written estimate rather than showing up as a surprise mid-project.
On incentives, Seattle City Light offers rebates on qualifying heat pump installations for its customers, and Washington State administers additional heat pump incentive programs alongside federal energy-efficiency tax credits. Ask the contractor to confirm the specific model qualifies, state the incentive amount in writing, and tell you who is responsible for filing the paperwork.
Get permit numbers, equipment models, duct or ductless scope, electrical scope, incentive handling, and warranty terms in writing before signing. That level of detail is what separates a well-run Seattle install from an expensive surprise.
Getting matched with a Seattle HVAC company
Henry does not sell your contact information to every company in the metro. You describe the job and your ZIP code, and up to three vetted Seattle HVAC contractors with active L&I registration and insurance follow up with written quotes.
Three quotes matters more in Seattle than in a lot of markets, because the right answer varies so much by house. One contractor may propose ductless mini-splits, another a full duct retrofit, another a ducted heat pump conversion off an old oil furnace. Comparing those approaches side by side is how you land on the right fit for your specific home instead of the one solution a single company happens to specialize in.
Areas Henry covers
Ballard · Wallingford · West Seattle · Beacon Hill · Queen Anne · Rainier Valley · Green Lake · Magnolia · Capitol Hill · Fremont
Common questions
Do I need a permit to install AC or a heat pump in Seattle?
Yes. The Seattle Department of Construction and Inspections (SDCI) issues mechanical permits for HVAC installs, replacements, and duct work inside city limits, with an inspection required to close it. Heat pump conversions often also need a separate electrical permit.
Why is ductless so common in Seattle instead of central AC?
A large share of Seattle's housing stock, especially Craftsman and pre-1950 homes in Ballard, Wallingford, Beacon Hill, and Rainier Valley, was built with no ductwork or with ducts sized only for heating. Ductless mini-splits avoid the cost and disruption of adding or rebuilding ductwork.
How do I verify a Washington HVAC contractor?
Search the company's registration number on the Washington L&I contractor lookup and confirm active status, bond, and insurance. If the job needs new wiring, confirm separately that a licensed electrician is doing that portion, since HVAC/R and electrical are different license categories in Washington.
How much does a heat pump conversion cost in Seattle?
A ducted heat pump conversion replacing a gas or oil furnace typically runs $12,500 to $24,000 before incentives. Seattle City Light and Washington State heat pump rebates, plus federal tax credits, can reduce that meaningfully depending on the equipment and your utility.
When is the best time to buy cooling in Seattle?
February through May. Once summer heat events start, installer schedules book out for weeks and prices firm up, making it harder to compare quotes calmly.
What happens if I still have an oil furnace?
Many Seattle homeowners are converting directly from oil to a heat pump rather than replacing with another oil or gas furnace. That job includes professional oil tank decommissioning and typically runs $9,500 to $22,000 depending on tank removal and electrical work needed.
Seattle guides from The Henry Files
Nearby Washington markets
Sources
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