HVAC Companies in Washington

Short answer: Exchange lists 7 HVAC contractors in Washington. Washington has no stand-alone state HVAC license. Instead, the Department of Labor and Industries registers HVAC firms as construction contractors under chapter 18.27 RCW, which requires a $15,000 specialty or $30,000 general contractor bond and liability insurance. Any line-voltage or control wiring also needs an electrical contractor license and a certified electrician, such as an 06A HVAC/refrigeration specialist. The 2021 Washington State Energy Code, in force since March 15, 2024, restricts fossil fuel and electric resistance heating in commercial buildings.

Registering agency

The Washington State Department of Labor and Industries (L&I) registers HVAC contractors under chapter 18.27 RCW and lists HVAC among the 63 specialties that require contractor registration.

Bond and insurance

Since July 1, 2024, Washington contractors need a $15,000 bond (specialty) or $30,000 bond (general), plus liability insurance of $200,000 public liability and $50,000 property damage, or $250,000 combined.

Electrical certification

HVAC electrical work in Washington requires an L&I electrical contractor license, which carries a $4,000 bond, and certified 06A or 06B HVAC/refrigeration specialty electricians under WAC 296-46B-920.

Energy code

The 2021 Washington State Energy Code took effect March 15, 2024. The State Building Code Council has set May 3, 2027 as the effective date for the 2024 code cycle.

Refrigerant rules

Ecology's Refrigerant Management Program requires owners of Washington systems holding 50 pounds or more of refrigerant with a GWP of 150 or higher to register, with deadlines phased in by system size through March 15, 2028.

Lien deadline

In Washington a lien claimant must record a notice of claim of lien within 90 days of last furnishing labor or materials under RCW 60.04.091, then sue within eight months.

Do HVAC contractors need a license in Washington?

Washington does not issue a single statewide HVAC or mechanical contractor license of the kind found in many other states. Heating, ventilation and air conditioning firms are instead regulated through several overlapping credentials, most of them run by the Department of Labor and Industries, known as L&I. The base requirement is contractor registration under chapter 18.27 RCW, which applies to anyone who, as an independent business, builds, remodels, repairs or improves real property. L&I lists HVAC as one of the 63 specialties that require registration, and it is illegal to bid, advertise or perform HVAC work in Washington without an active registration.

Registration comes in two classes. A general contractor can perform most types of construction and can hire subcontractors in several specialties. A specialty contractor, which is how most dedicated HVAC companies register, may work only in its registered specialty and cannot hire subcontractors. An HVAC firm that wants to take a whole renovation, including framing, drywall or roofing around new equipment, either needs general registration or needs the owner or a general contractor to hire those trades separately.

Registration alone does not cover electrical work. Almost every heat pump, furnace, air handler and rooftop unit has line-voltage connections and low-voltage controls, and in Washington that wiring is electrical work under chapter 19.28 RCW. A company that does it must hold an L&I electrical contractor license and employ certified electricians, usually specialty electricians in the 06A HVAC/refrigeration or 06B HVAC/refrigeration restricted categories. Gas piping, refrigeration in some cities, and boilers bring further requirements, which are covered below.

For an owner or general contractor choosing an HVAC subcontractor in Washington, this means a single license number is not enough. You need to check the contractor registration, the electrical contractor license, the individual certificates of the technicians who will be on site, and any city trade license where the project is located. L&I's Verify a Contractor, Tradesperson or Business tool shows the registration, bond, insurance and electrical license status for each company.

What bond and insurance must a Washington HVAC contractor carry?

Under RCW 18.27.040, every registered contractor must keep a continuous surety bond, or an assignment of savings, on file with L&I. The amounts went up on July 1, 2024, the first increase since 2001. General contractors now need $30,000, up from $12,000, and specialty contractors need $15,000, up from $6,000. Contractors had to switch to the higher bond at their next renewal, so after the two-year phase-in every active registration should now show the new amount. A Washington HVAC specialty contractor whose L&I record still shows a $6,000 bond deserves a closer look.

The bond guarantees that the contractor will pay its workers, employee benefits, state taxes and contributions, and suppliers and equipment renters, and that it will pay amounts awarded against it for breach of contract, including improper work. L&I says half of each bond is reserved for consumers, with the other half available to workers, suppliers and taxing agencies. To collect, a customer has to sue the contractor and the bond and win a judgment, and the protection applies only if the contractor was registered. Even $15,000 can run out quickly on a failed commercial system replacement, which is why owners usually ask for a separate performance bond on larger jobs.

Registration also requires general liability insurance of at least $200,000 for public liability and $50,000 for property damage, or a $250,000 combined single limit, with L&I listed as certificate holder. These are minimums for registration, not a sensible project limit. Commercial owners and general contractors in Washington typically require much higher limits, completed-operations coverage, and additional insured status written into the subcontract.

Washington's workers' compensation system is also different from most states. Employers must buy industrial insurance through L&I's state fund unless they qualify to self-insure, and private workers' compensation policies are not sold for in-state work. An HVAC subcontractor's certificate of insurance will therefore not show workers' compensation the way it would in other states. Ask instead for proof that the firm's L&I industrial insurance account is active and in good standing.

Which licenses, permits and registrations apply in Washington?

How do I check an HVAC contractor in Washington before I sign?

7 checks, in order, using the Washington registers and rules described on this page:

1. Search the firm on L&I's Verify a Contractor, Tradesperson or Business tool and confirm an active HVAC specialty or general registration, a bond of $15,000 or $30,000, and current liability insurance.
2. On the same L&I record, confirm the company holds an electrical contractor license under RCW 19.28.041, and ask for the 06A, 06B or journey level certificate numbers of the technicians who will wire the equipment.
3. Match the certificate to the equipment: require 06A or journey level electricians for systems with a primary connection over 250 volts single phase or 120 amps, as WAC 296-46B-920 requires.
4. Get the RCW 18.27.114 disclosure statement before work starts on any residential job of $1,000 or more, or any commercial job from $1,000 up to $60,000.
5. For work inside Seattle, confirm the contractor holds a Seattle refrigeration and air conditioning contractor's license with a designated journey refrigeration mechanic of the right class.
6. If the site has a system holding 50 pounds or more of high-GWP refrigerant, confirm it is registered with Ecology's Refrigerant Management Program and that the contractor will provide leak inspection and repair records.
7. Confirm which Washington State Energy Code edition the permit will be reviewed under, given the 2024 codes' May 3, 2027 effective date, and make the contractor responsible for pulling the mechanical and electrical permits.

Which electrical certifications do HVAC technicians need in Washington?

Washington's electrical licensing rules in chapter 296-46B WAC create two specialty electrician certificates aimed at HVAC and refrigeration work. The 06A HVAC/refrigeration specialty is not limited by voltage, phase or amperage. It covers installing, repairing and maintaining line-voltage components inside HVAC and refrigeration equipment, Class 2 low-voltage control wiring, and the internal components of the equipment's disconnect or controller as long as it is not inside a motor control center or panelboard. It also covers flexible supply whips up to six feet long. No unsupervised electrical trainee may work on any part of an HVAC or refrigeration system containing a circuit rated over 600 volts, whether or not it is energized.

The 06B HVAC/refrigeration restricted specialty covers similar tasks but cannot do any electrical work where the primary power connection to the system exceeds 250 volts single phase or 120 amps. That fits most residential split systems and light commercial packaged units, but not larger three-phase rooftop units, chillers or industrial refrigeration. Under WAC 296-46B-945, an 06A candidate needs 4,000 hours of supervised experience to sit the exam and to be certified. An 06B candidate can test after 1,000 hours but needs 2,000 hours for certification, and trainees work under full supervision until they pass the exam.

Neither HVAC specialty may install line-voltage controllers or disconnect switches outside the equipment, run branch circuit or feeder conductors, or install panelboards or raceway systems. There is one narrow exception. When HVAC equipment is replaced, an 06A electrician may swap a surface-mounted disconnect on the unit for a like-in-kind one rated no more than 20 amps at 120 volts, using the existing wiring method. Anything larger, such as a new circuit for a heat pump, belongs to a general journey level or residential electrician working for a licensed electrical contractor.

The company itself needs an electrical contractor license under RCW 19.28.041, backed by a $4,000 bond, and the bond increase for registered contractors did not change this electrical bond. Washington has adopted the 2023 edition of the National Electrical Code in WAC 296-46B-010. Electrical work also needs its own permit and inspection, separate from the mechanical permit, which L&I issues in most of the state, though some cities, Seattle among them, run their own electrical permitting and inspection.

What does the Washington State Energy Code require for heating and cooling systems?

The State Building Code Council adopts Washington's building codes, and the 2021 editions with state amendments took effect on March 15, 2024. They include the International Building Code, International Residential Code, International Mechanical Code, Uniform Plumbing Code and the Washington State Energy Code in residential and commercial versions. The energy code is among the strictest in the country and has a direct effect on HVAC equipment selection, so the code edition on the permit application matters to anyone pricing a system.

For commercial buildings, the 2021 commercial energy code limits fossil fuel and electric resistance space heating, with listed exceptions, and makes heat pump water heating the primary service water heating system. After a federal appeals court decision widened the reach of preemption under the federal Energy Policy and Conservation Act, the council revised those provisions in rulemaking filed as WSR 24-03-085, effective March 15, 2024. The changes added a fossil fuel compliance path that allows gas-fired HVAC and water heating equipment if the project earns extra efficiency credits, restored electric resistance supplemental heat for air-source and ground-source heat pumps, and required electrification readiness, such as a spare conduit to the location of a future replacement heat pump.

Under the revised commercial rules, the primary heat pump water heating system must still be sized to deliver at least 50 percent of the calculated demand, with electric resistance or fossil fuel allowed only as a supplement. On the residential side, the 2021 code requires builders to earn additional energy efficiency credits from a menu of options, and high-efficiency heat pumps are one of the main ways to earn them. In practice, an HVAC contractor's equipment schedule often decides whether a Washington project passes the energy review.

The next code cycle is close. The council scheduled final adoption of the 2024 building, residential, mechanical, fire and plumbing codes for October 16, 2026. For the 2024 energy codes, it filed proposed rules on July 1, 2026, held hearings in August, and targeted final adoption for November 20, 2026. The council has set May 3, 2027 as the effective date for the 2024 codes, so projects permitted after that date will be reviewed under the new editions. Owners with design underway should ask their mechanical engineer and HVAC contractor which edition the permit will vest under.

How do Washington's refrigerant and clean building rules affect HVAC work?

Washington regulates hydrofluorocarbon refrigerants more tightly than federal law. The Department of Ecology's Refrigerant Management Program, adopted in chapter 173-443 WAC, applies to systems that use refrigerants with a global warming potential of 150 or more. Facilities are sorted by the full charge of their largest system: large systems hold 1,500 pounds or more, medium systems 200 to 1,499 pounds, and small systems 50 to 199 pounds. Owners and operators of covered systems must register them in Ecology's online reporting system.

The deadlines are phased. Large facilities had to register by March 15, 2024, medium facilities by March 15, 2026, and small facilities must register by March 15, 2028, with annual reports starting a year after registration for large and medium facilities. Large systems need monthly leak inspections from January 1, 2024, unless automatic leak detection is installed, and enclosed large systems needed automatic leak detection by January 1, 2025. Medium systems need quarterly inspections from January 1, 2026, and small systems need annual inspections from January 1, 2028. Leaks must be repaired within 14 days of detection, and records kept for at least five years.

For HVAC contractors serving supermarkets, cold storage, food processing, data centers and large commercial chillers, this creates recurring compliance work: leak inspections, repair documentation and data for the owner's annual report. Owners choosing a service contractor should ask how the firm documents inspections and repairs in a way that meets Ecology's recordkeeping rules, and whether its technicians handle low-GWP alternatives as systems are retrofitted.

The Clean Buildings Performance Standard, run by the Department of Commerce, adds pressure on existing commercial buildings. Tier 1 buildings must show compliance with energy use intensity targets and energy management requirements on a schedule set by floor area: June 1, 2026 for buildings over 220,000 square feet, June 1, 2027 for buildings over 90,000 square feet, and June 1, 2028 for buildings over 50,000 square feet. HVAC upgrades, controls work and recommissioning are usually the main ways owners meet their targets, so contractors with energy management and commissioning experience are in demand in Washington's commercial market.

What extra HVAC licensing and permitting rules apply in Seattle and other Washington cities?

Local governments in Washington issue mechanical permits under the state-adopted International Mechanical Code with Washington amendments, and many add their own trade licensing. Seattle is the clearest example. The Seattle Department of Construction and Inspections licenses refrigeration trades separately from the state. A journey refrigeration mechanic license is required to install, repair or alter refrigeration or air conditioning equipment in the city. It comes in Class A for equipment using freon-type refrigerants, Class B for ammonia systems, and Class C for all types.

Seattle also requires a business-level refrigeration and air conditioning contractor's license to install, repair or alter that equipment, including planning, engineering and supervising the work, and the contractor must name an employee who holds a journey refrigeration mechanic license. A refrigeration operating engineer license covers full-time employees who run systems in buildings owned or operated by their employer, such as cold storage plants. All Seattle refrigeration licenses renew every year by June 30, and if the designated journey mechanic's license lapses, the contractor's license expires with it.

Eligibility for the Seattle journey refrigeration mechanic exam requires, for example, three years of experience in refrigeration installation and repair as an apprentice or journeyman, or two years at a recognized technical school plus one year in the trade. The passing score is 70 percent. HVAC contractors who mostly work in suburban King, Pierce or Snohomish County should not assume they can take a Seattle job without first getting these city credentials in place.

Elsewhere in Washington, mechanical, electrical and plumbing permits are usually separate. A heat pump changeout may need a city or county mechanical permit plus an electrical permit from L&I or the local electrical authority. Larger cities such as Spokane, Tacoma, Bellevue and Vancouver each set their own permit portals, fees and inspection scheduling. Owners should make the contractor responsible in writing for pulling every permit and arranging final inspections, because unpermitted HVAC work can delay a sale, an insurance claim or a utility rebate.

What consumer protections apply to residential HVAC jobs in Washington?

RCW 18.27.114 requires a contractor to give the customer a written disclosure statement before starting work on any residential project of four or fewer units, or accessory structures on that property, when the bid or contract price is $1,000 or more. The same applies to commercial jobs of at least $1,000 but less than $60,000. The prescribed notice tells the customer the contractor's registration number, the bond amount and the registration expiration date, warns that the bond may not cover a claim, and explains that subcontractors and suppliers may have lien rights against the property. A contractor that skips the disclosure cannot claim a lien on that job.

The rules on how contractors present themselves also protect homeowners. Under RCW 18.27.100, all advertising, contracts, cards, signs and documents must show the contractor's name and address exactly as registered, and a contractor may not do business under a name it has not registered. A furnace or heat pump offer from a company whose name does not match any L&I registration is a warning sign. L&I advises consumers to check registrations and bond amounts at ProtectMyHome.net or by phone before hiring.

Washington's lien law, chapter 60.04 RCW, gives contractors, subcontractors and suppliers lien rights. Under RCW 60.04.031, suppliers and others who are not in direct contract with the owner generally must give the owner written notice of the right to claim a lien, and that notice protects only materials and services supplied from 60 days before it was given. Homeowners who receive these notices from an HVAC equipment distributor should get lien releases before making their final payment to the installer.

Many Washington HVAC replacements are now paid for in part by utility or state rebates for heat pumps and weatherization. Rebate programs often require a qualified or participating contractor, specific equipment efficiency ratings and proof of a passed permit inspection. Homeowners should check the program's contractor list before signing and make sure the contract states who applies for the rebate and what happens if it is denied.

What climate, lien and payment issues should Washington project owners plan for?

The Cascade Range splits Washington into two very different HVAC markets. West of the mountains, in Seattle, Tacoma, Olympia, Everett and Bellingham, the marine climate is mild and damp, cooling loads were historically low, and many older homes had no air conditioning. Recent heat waves and wildfire smoke have pushed up demand for heat pumps with cooling and for better filtration and ventilation. East of the Cascades, in Spokane, Yakima, Wenatchee and the Tri-Cities, summers are hotter and winters much colder, so heat pump selection needs to account for low-temperature capacity and supplemental heat.

Wildfire smoke affects both regions and has become a design issue for schools, offices and multifamily buildings. Owners should ask HVAC contractors about filter upgrades the existing fans can handle, outdoor air control during smoke events, and how the work fits with energy code ventilation and economizer requirements. In seismic western Washington, equipment anchorage and bracing must meet the building code's seismic provisions, which matters for rooftop units and suspended equipment.

On payment, Washington's lien statute sets strict deadlines. Under RCW 60.04.091, a claimant must record a notice of claim of lien in the county where the property is located no later than 90 days after it last furnished labor, professional services, materials or equipment. Under RCW 60.04.141, the lien expires eight months after recording unless the claimant files a foreclosure action in superior court in that county within that time and serves the owner within 90 days of filing. Because of these short windows, HVAC subcontractors waiting on slow payment from a general contractor have to watch the calendar closely.

Public projects use different protections. Under RCW 39.76.011, state agencies, counties, cities, school districts and other public bodies owe interest of 1 percent per month on late payments. Payment counts as timely if it goes out by the contract date, and in no case later than 30 days after a properly completed invoice or receipt of the work, whichever is later. RCW 60.28.011 requires public improvement contracts to hold retainage of no more than 5 percent as a trust fund for claims by subcontractors, suppliers and the state. On public mechanical jobs, contractors must also follow Washington prevailing wage rules administered by L&I.

What has changed recently, or is about to change, for HVAC contractors in Washington?

Last reviewed October 19, 2026 against the primary sources listed below. Dates are effective dates unless marked otherwise.

• June 1, 2027 — Scheduled: Washington Clean Buildings Tier 1 buildings over 90,000 square feet must show compliance with energy use intensity targets and energy management requirements.
• May 3, 2027 — Scheduled: Washington's 2024 code cycle, including building, mechanical, plumbing and energy codes, takes effect, as set by the State Building Code Council.
• March 15, 2026 — In force: Washington Refrigerant Management Program deadline for medium systems of 200 to 1,499 pounds to register with Ecology.
• July 1, 2024 — In force: Washington contractor bonds rose to $15,000 for specialty and $30,000 for general contractors, the first increase since 2001.
• March 15, 2024 — In force: The 2021 Washington State Energy Code took effect, restricting fossil fuel and electric resistance heating in commercial buildings.

Where can I verify a license and check the source in Washington?

Every figure and rule on this page can be checked against the primary source. These are the offices that publish them. Confirm current requirements directly before you rely on any of them:

Washington State Department of Labor & Industries — Register as a Contractor; Washington State Legislature — RCW 18.27.040 Bond or other security required; Washington State Legislature — WAC 296-46B-920 Electrical license and certificate types and scope of work; Washington State Building Code Council — 2024 Codes adoption announcements; Washington State Department of Ecology — Refrigerant Management Program; Washington State Legislature — RCW 60.04.091 Recording, time and contents of lien.

Nearby regions and related trades

HVAC contractors in other regions: Arizona, British Columbia, California, Florida, Georgia, Illinois, Maryland, Nevada, New York, North Carolina, Ontario, Pennsylvania, South Carolina, Texas, Virginia.

Other trades in Washington: Electrical, Envelope, General Contracting, Mechanical, Renovation & Remodeling, Restoration, Roofing & Waterproofing.

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