Washington’s 06B certificate — formally the HVAC/refrigeration – Restricted certificate (06B) — is a specialty electrician certificate of competency issued by the Washington Department of Labor and Industries (L&I) under RCW 19.28 and WAC 296-46B. It is the restricted sibling of the 06A specialty: an electrical certificate for HVAC and refrigeration work, bounded by a stated power-connection ceiling and examined by PSI in two sections that must each be passed. The PassProfessor Washington 06B HVAC/R Restricted Specialty program prepares candidates for that examination and for the boundary judgement the certificate demands. The full companion is the Washington 06B HVAC/R Restricted Specialty Exam Guide.
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A certificate defined by its boundary
Some credentials are defined by their breadth. The 06B is defined by its edge, and this program is organised around that edge from the first page, because the edge is what a holder uses every working day.
The certificate sits in Washington’s electrical family, under the same framework as its full-specialty sibling. L&I’s governing principle applies unchanged: to work in the electrical construction trade in Washington, you must have a valid electrician certificate issued by L&I. The 06B is one of that family’s specialty categories, with an electrical scope written in WAC 296-46B-920.
Washington has no HVAC contractor license and no mechanical license of this kind, and no examination for either exists in the sources governing this credential. The 06B is not a contractor credential and not authority for mechanical work in itself.
What makes the 06B restricted is stated by the rule in numbers: a power-connection ceiling, a fence for low-voltage work outside residential occupancies, and two prohibitions binding this certificate alone. A candidate who cannot state the ceiling precisely, and place described work on the correct side of it, is not ready for this examination. That is why the boundary leads this program.
The boundary, in the rule’s own terms
The power-connection ceiling. Under WAC 296-46B-920(2)(f)(iv), the (06B) specialty may not perform any electrical work where the primary electrical power connection to the system exceeds: 250 volts, single phase, or 120 amps. Both prongs matter: a connection above either figure is outside the certificate. The sibling comparison is exact: where the 06B rule states a ceiling, the 06A rule states that the (06A) specialty is not limited by voltage, phase, or amperage. No tonnage or system-size limit appears in the rule for this certificate.
The three-story low-voltage fence. For Class 2 low-voltage control wiring, the 06B may work in all residential occupancies. In other occupancies, the permission holds only where the occupancy has no more than three stories on or above grade — a taller non-residential occupancy falls outside this certificate even where the connection sits under the ceiling. The sibling’s permission is broader, reaching all occupancies regardless of stories.
The two bars that bind 06B alone. Beyond the shared prohibitions, the rule bars this certificate from the allowed telecommunications and low-voltage wiring when it runs in a conduit or raceway system, and from any wiring in NEC Articles 500 through 516 classified locations — a total bar, where the sibling’s reaches only wiring outside the equipment.
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Washington 06B HVAC/R Restricted Specialty: the HVAC/refrigeration – Restricted certificate (06B) |
| Regulator | Washington Department of Labor and Industries (L&I), under RCW 19.28 and WAC 296-46B |
| Examination vendor | PSI Services LLC, under contract to L&I; L&I approval and an Exam Unique ID required first |
| Examination structure | Two sections on the same day: NEC & Theory — 34 questions, 2 hours; Washington Code — 20 questions, 1 hour; 54 questions, 3 hours, plus 10 unscored experimental questions |
| Passing standard | Each section must be passed independently — see the verbatim forms below |
| Book policy | Open book |
| Tested code layer | 2020 National Electrical Code, plus the current RCW 19.28 and WAC 296-46B |
| Adopted field layer | 2023 National Electrical Code under WAC 296-46B-010 — separate from the tested edition |
| Experience gates | 1,000 hours for examination eligibility; 2,000 hours for certification |
| Credential term | Three-year renewal cycle |
| Renewal education | 24 hours of continuing education per cycle (8 / 4 / 12 split) |
| Administrator note | PassProfessor is independent and is not affiliated with the Washington Department of Labor and Industries |
The passing standard, in its published forms
Washington publishes this standard in two forms, and this program states it only in those forms. The PSI bulletin states: “You must score 70% to pass.” L&I states the operative per-section form: “You must pass each section of the examination with a score of 70% or greater.”
For the restricted candidate the per-section form carries particular weight: the sections are uneven in size — 34 questions against 20 — and in kind, one testing code and theory, the other the Washington law that draws this certificate’s boundary.
Two sections: a smaller code paper, the same Washington paper
The NEC & Theory section carries 34 questions in 2 hours. Its largest knowledge areas in the bulletin outline for the Electrician column are General Trade Knowledge & Theory, at 6 questions, and two areas at 5 each: wiring methods under NEC Articles 300 through 398, and the area covering NEC Articles 430 through 450 — motors, HVAC, generators and transformers. The bulletin notes that the count in any individual area is approximate. Theory questions are general and may include general mathematics and theory computation.
The Washington Code section carries 20 questions in 1 hour — the same size as the full specialty’s Washington section, examining the same current RCW 19.28 and WAC 296-46B. For this certificate, that section is where the credential itself is examined: the ceiling, the fence, the additional bars, supervision and the hours rules all live in its material. The bulletin states the basis directly: all law, rule and code questions are based on the current RCW 19.28 and WAC 296-46B, and the 2020 National Electrical Code. Only the outline’s Electrician column — 34 and 20 — describes this examination.
Open book, under the same discipline
All examinations in this program are open book: “All examinations are open book.” L&I’s bring-list names the 2020 National Electrical Code book, printed Chapter 19.28 RCW and Chapter 296-46B WAC in a three-ring binder, and any original copyrighted material. A silent, nonprinting, nonprogrammable calculator is permitted. Permanent index tabs, highlighting and underlining are allowed; handwritten notes and removable tabs are not. Both sections reward books organised for retrieval — above all the binder, because the boundary questions live in the rule.
Tested edition and adopted edition: separate layers
The examination tests the 2020 National Electrical Code, with the current RCW 19.28 and WAC 296-46B.
Field installations answer to a different layer. WAC 296-46B-010 adopts the 2023 edition of the National Electrical Code, effective April 1, 2024, and already provides that, effective December 31, 2026, the 2026 edition is adopted and replaces the 2023 edition. Tested NEC 2020 is not adopted NEC 2023. A third layer belongs to the field alone: Chapter 51-52 WAC adopts the 2021 International Mechanical Code with Washington amendments, effective March 15, 2024 — not an examination reference for this NEC examination, and field context only.
Two hours figures, two different doors: 1,000 to sit, 2,000 to certify
No distinction in this program is printed more carefully than this one. Under WAC 296-46B-945, Table 945-1, the 06B row carries two figures: the minimum work experience required to be eligible for examination is 1,000 hours, and the work experience required for certification is 2,000 hours. Examination eligibility and certification are different doors, and this program states the two figures distinctly every time either appears.
The rule builds a mechanism around the gap. Until the examination is passed, the trainee works under 100 percent supervision. Once it is passed, the holder of a modified trainee certificate — the 0 percent supervision certificate — may work unsupervised while completing the balance of the 2,000 hours. That certificate is valid for no more than two years, and only one may be held in a specialty; if the hours are not completed in time, the trainee moves to a 75 percent supervision certificate until they are.
The baseline gates stand around the hours: a current electrical training certificate, an employer employing an appropriate certified electrician, and 24 hours of basic classroom instruction — the figure for the band where 2,000 or more but less than 4,000 hours is required. Applicants must be at least 16, and no more than half of the minimum experience may come from a training school program; an appropriate two-year registered apprenticeship route is also provided. The 2,000 certification hours may later be credited toward the 4,000 hours required for 06A certification, but not toward the general journey level (01) examination.
Scope inside the boundary: what the certificate may still do
A ceiling is not an absence of scope. Within the ceiling, the rule gives this certificate the same in-equipment permissions as its sibling: line voltage components within the equipment, including product-illumination luminaires inside refrigeration cases and factory-authorised accessories; internal components of the equipment disconnecting means or controller, if not located in a motor control centre or panelboard; short sections of raceway for physical protection of low-voltage cables; supply whips not over six feet; and Class 2 low-voltage control wiring within the fence’s conditions. Replacements must be like-in-kind or the manufacturer’s authorised replacement.
The shared prohibitions bind this certificate in full. It may not install line voltage controllers or disconnect switches external to the equipment, apart from the same narrow exception — a like-in-kind surface-mounted disconnect enclosure rated not more than 20 amperes and 120 volts, up to ten feet of protective raceway, not terminating in a panelboard. It may not install integrated building control systems other than HVAC and refrigeration systems; stand-alone line voltage equipment unless exclusively controlled by and integrally connected to the system; building-lighting luminaires; raceway or conduit systems; line voltage service, feeder or branch circuit conductors, apart from the narrow supplementary-device exception; or panelboards, switchboards or motor control centres external to the system — and then the two 06B-only bars stated above.
Fees, kept by instrument
The examination fee is paid to PSI, which charges per hour on a published scale from $45.00 for one hour to $105.00 for seven hours. This examination totals three hours — the $65.00 row; the sibling’s $75.00 four-hour row is not this program’s fee. Registration fees are not refundable or transferable, and retests are billed per hour for the sections retaken. L&I states that fees paid to PSI are in addition to any application fees paid to L&I.
The state instrument is separate: under WAC 296-46B-909, the application — including the original certificate and processing — is $114.60, of which $44.20 is nonrefundable after submission. Renewal is $106.40 on paper and $92.60 fully online; late renewal is $212.90 or $185.30. No combined total is a fee.
Sitting, results and retakes
Candidates must first be approved by L&I, which sends an eligibility notice carrying an Exam Unique ID used to register with PSI. The examination is computer-administered at PSI centres, and the score appears on screen immediately. A candidate has one year from the approval letter date to pass all sections; passed sections carry only within that period, and the first attempt must consist of all sections. At least 14 days must pass between attempts; after failing any section three times within a year, 90 days must pass between further attempts. Results may be challenged in writing to the Chief Electrical Inspector within 20 days, under WAC 296-46B-960. For this certificate, the retake clock is also supervision planning: a passer moves into the modified-trainee position, while a candidate still working toward a pass remains under 100 percent supervision.
Staying certified: the three-year cycle and its 24 hours
The certificate renews on a three-year cycle, with 24 hours of continuing education in the cycle: 8 hours on currently adopted NEC changes, 4 hours on Chapter 19.28 RCW and related Chapter 296-46B WAC, and 12 hours in any other approved course. The same class may not be taken twice for credit.
What the PassProfessor program will cover
The boundary as the curriculum’s spine. This program teaches the certificate from its edge inward: the ceiling drilled as placement judgement on described systems; the three-story fence applied occupancy by occupancy; the two 06B-only bars held distinctly from the shared prohibitions.
The hours distinction, printed exactly. Examination eligibility at 1,000 hours and certification at 2,000 hours are taught as the two-step structure the rule builds — 100 percent supervision before the pass, the modified-trainee position after it. No page of this program states a flat hours figure.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with L&I or PSI. Completing this program confers no certificate and no eligibility; L&I alone certifies electricians.
Tell me when enrollment opens. The Washington 06B HVAC/R Restricted Specialty program is in the works as part of our catalog; enrollment is not yet open. Leave an email address and PassProfessor will write when the program is ready — only about this program. No date is promised. For the complete account, read the Washington 06B HVAC/R Restricted Specialty Exam Guide.
Frequently asked questions
What makes the 06B “restricted”?
Its scope ceiling, stated in WAC 296-46B-920: no electrical work where the primary electrical power connection to the system exceeds 250 volts single phase, or 120 amps. A three-story condition on non-residential low-voltage work and two additional prohibitions complete the restriction.
Is the 06B an HVAC contractor license?
No. It is a specialty electrician certificate issued by L&I. Washington has no HVAC contractor license or mechanical license of this kind in this framework.
How is the examination structured?
Two sections on the same day: NEC & Theory, 34 questions in 2 hours, and Washington Code (RCW & WAC), 20 questions in 1 hour — 54 questions, 3 hours in total, plus 10 unscored experimental questions. L&I approves candidates first; PSI administers the examination.
What score passes?
The bulletin states: “You must score 70% to pass.” L&I states: “You must pass each section of the examination with a score of 70% or greater.” Each section must reach it independently.
How many hours do I need — 1,000 or 2,000?
Both, at different doors: examination eligibility requires 1,000 hours; certification requires 2,000. After passing, the balance is completed under the modified trainee certificate, valid for no more than two years.
What can an 06B holder work on?
Within the ceiling: line voltage components inside the equipment, internal disconnect and controller components outside a motor control centre or panelboard, short protective raceway sections, supply whips not over six feet, and Class 2 low-voltage control wiring in all residential occupancies and in other occupancies of no more than three stories on or above grade — subject to the shared prohibitions and the two 06B-only bars. The 06A carries no such ceiling.
What do the examination and the certificate cost?
Two separate instruments: PSI charges $65.00 for the three-hour examination; L&I’s application is $114.60. Renewal is $106.40 on paper or $92.60 fully online. No combined total is a fee.
When does enrollment open?
The program is in the works; enrollment is not yet open.