PL03 and PL03A Are Different Specialty Plumber Certifications

Washington Labor & Industries separates pump plumbing into two specialty classifications. PL03 is the broader Pump and Irrigation specialty. PL03A is the more limited Domestic Well specialty.

What Work Is Covered by PL03 Pump and Irrigation?

Washington rules define PL03 as installation, maintenance, and repair of equipment used to acquire, treat, store, or move water suitable for drinking, other domestic purposes, or irrigation.

The specialty can include:

• One or more water pumps
• Pressure tanks
• Storage tanks
• Filtration equipment
• Water-treatment equipment
• Valves
• Related piping within the specialty scope
• Domestic water pumping systems
• Public water systems within applicable limits
• Irrigation pumping equipment

Washington rules also place boundaries on what can be worked on when equipment is located inside a residential structure. Work outside the specialty definition must be performed under the appropriate plumbing certification.

What Work Is Covered by PL03A Domestic Well?

PL03A is the limited-volume domestic pump specialty. Washington rules limit this certification to equipment used to acquire, treat, store, or move water for drinking or domestic purposes on pumping systems not exceeding 100 gallons per minute.

Labor & Industries also describes the Domestic Well combination trade as using a pump not exceeding 100 gallons per minute or 7.5 horsepower, single phase.

The system can include:

• Pumps
• Pressure tanks
• Storage tanks
• Filtration equipment
• Treatment equipment
• Valves and related plumbing components
• Piping connected to the permitted pump-system equipment

PL03A is useful for limited domestic-well systems, but it is not a shortcut to unrestricted pump and irrigation plumbing.

PL03 Requires 4,000 Hours of Plumbing Experience

To qualify for the Pump and Irrigation specialty plumber certification, Washington currently requires at least two years, or 4,000 hours, working in the specialty under the supervision of an appropriate certified plumber.

Labor & Industries specifically excludes PL03A and PL30 from the certifications that can provide the required supervision for the PL03 experience pathway.

PL03A Requires 2,000 Hours of Plumbing Experience

Domestic Well candidates have a shorter plumbing-experience pathway. Washington currently requires at least one year, or 2,000 hours, of work in the specialty under a certified plumber.

PL30 Backflow certification does not qualify as the supervising certification for this pathway.

Your Experience Must Be Documented Before the Exam

Washington requires plumber trainees to have their affidavits of experience on file with Labor & Industries before applying for examination eligibility.

Keep careful records of your hours, employer, supervising plumber, specialty classification, dates, and type of work. Pump-system work can cross several trade boundaries, so vague records are not your friend.

For help organizing licensing paperwork, review 1ExamPrep application services.

Pump Work Also Requires Electrical Certification

Washington treats domestic-well and pump-and-irrigation work as a combination plumbing and electrical trade. Labor & Industries states that workers doing pump and piping work on domestic water systems and irrigation water systems must have the proper plumbing and electrical credentials.

The plumbing certification does not automatically authorize the electrical side of the job. Electrical work involving pump motors, controls, branch circuits, feeders, services, and related equipment is governed separately by Washington electrical licensing rules.

Contractors Need Both Plumbing and Electrical Licensing Too

Washington also requires contractors working in this trade to hold the proper contractor licensing for both sides of the work.

Labor & Industries provides a combined Pump Installer Plumbing and Electrical Contractor pathway for businesses specializing in Domestic Well or Pump and Irrigation work.

The contractor business must have the required designated certified people assigned to the plumbing and electrical sides, along with the bonding, insurance, and contractor-registration requirements that apply to the business.

This is different from your individual PL03 or PL03A certificate.

The Current Specialty Exam at a Glance

The Approved Exam Reference

PSI currently lists the 2015 Uniform Plumbing Code with Washington State Amendments as the approved reference for the pump specialty examination.

Washington Labor & Industries also states that the Domestic Pump and Pump & Irrigation Specialty Exam is based on Chapters 2, 3, 6, and 16 of the UPC and Washington amendments.

Chapter 2: Definitions Matter More Than They Look

Definitions can seem like the appetizer before the "real" code, but specialty licensing questions often depend on exact words.

Know the meaning of terms connected with potable water, water supply, approved materials, pressure, treatment equipment, pumps, fixtures, piping, and specialty systems.

A question may appear to ask about a pump installation when it is really testing whether you understand the code definition of the system or material involved.

Chapter 3: General Plumbing Requirements

Chapter 3 contains broad plumbing rules that can affect nearly any pump-system installation.

Review:

• Approved materials
• Workmanship
• Protection of piping
• Support
• Accessibility
• Connections
• Equipment installation
• General system requirements

General rules are easy to overlook because they are not labeled "pump rules." The exam can still use them.

Chapter 6: Water Supply and Distribution Is the Core Study Area

Pump and irrigation work lives very close to water-supply rules, so Chapter 6 deserves serious attention.

Study:

• Potable-water protection
• Water-supply materials
• Pressure requirements
• Pipe sizing
• Valves
• Service connections
• Water distribution
• Cross-connection concerns
• Pressure-regulating equipment
• Water-system components

Practice locating tables and exceptions quickly. Two minutes per question disappears fast when you are wandering through the index like it owes you money.

Chapter 16: Alternate Water Sources

Chapter 16 belongs in the current exam scope and should not be ignored simply because Chapter 6 feels more familiar.

Review alternate water-source concepts, storage, system separation, identification, treatment, and the code rules that can apply when water is collected, stored, or reused.

Irrigation and domestic-water systems can involve equipment that sits right at the boundary between ordinary potable-water distribution and specialty water-source systems.

Open-Book Rules From the Current PSI Bulletin

The current PSI bulletin allows candidates to bring the approved pump-specialty plumbing reference into the examination center, but the book must follow PSI's rules.

• The reference may be highlighted before the exam
• The reference may be underlined before the exam
• The reference may be annotated before the exam
• Permanent tabs or indexes are allowed
• Temporary tabs such as Post-It notes are not allowed
• No additional loose or attached papers are allowed
• You may not write in the reference during the examination

Prepare the book before test day and practice with the exact layout you plan to use.

Open-Book Strategy for a 90-Minute Exam

Open book does not mean slow book. With 45 questions in 90 minutes, you have about two minutes per question.

1. Identify the chapter first. Is this terminology, a general rule, water supply, or alternate water?
2. Answer direct knowledge questions quickly. Do not look up everything just because a book is available.
3. Use the index when the subject is unclear.
4. Use permanent tabs for high-use chapters and tables.
5. Flag long searches and return later.
6. Read exceptions and notes before choosing the answer.

The goal is not to memorize every code section. The goal is to recognize the problem and get to the controlling rule quickly.

The Application Process Comes Before PSI Scheduling

Washington requires candidates to apply to Labor & Industries for exam eligibility before they can schedule the plumbing examination with PSI.

Approved eligibility is currently valid for one year. For PL03 Pump and Irrigation and PL03A Domestic Well, Labor & Industries says online examination application is not currently available, so candidates use the mail application process.

If you fail, Washington requires a two-week, or 14-calendar-day, wait from the failed test date before retesting.

Current Application and Certification Fees

Labor & Industries currently lists a $202.10 plumbing examination application fee.

After successfully completing the exam, the current certification fee for Domestic Pump or Pump and Irrigation is $242.80.

PSI also charges its examination scheduling fee. The current PSI bulletin lists $52 for an individual exam portion. Confirm the amount shown during scheduling before payment.

PSI states that successful candidates have 90 days after passing to pay the certification fee. If that deadline is missed, retesting may be required.

Renewal Is Every 3 Years on Your Birthday

Washington currently renews PL03 Pump and Irrigation and PL03A Domestic Well plumber certificates every three years on the certificate holder's birthday.

The initial certificate can run from about 25 to 37 months depending on when it is issued relative to your birthday.

The current renewal fee is $242.80. The current late fee is another $242.80, making the total $485.60 when the late fee applies.

Continuing Education Combines Plumbing and Electrical

Because these specialties cross plumbing and electrical work, Washington's continuing-education rule reflects both sides.

PL03 and PL03A certificate holders currently need 24 hours of continuing education before renewal. Labor & Industries specifies:

• At least 12 hours of electrical education
• At least 12 hours of plumbing education in approved Code or Industry-Related Plumbing categories

Missing the continuing-education deadline can trigger late fees and block online renewal.

A Practical Study Plan

1. Learn PL03 and PL03A scope first. Know which credential you are pursuing.
2. Review UPC Chapter 2. Build a glossary of specialty terms.
3. Study Chapter 3. Focus on general installation and material rules.
4. Spend the most navigation time in Chapter 6. Water-supply rules are central to this trade.
5. Review Chapter 16. Do not ignore alternate-water requirements.
6. Practice pressure, flow, and water-distribution reasoning.
7. Review pump-system components. Pumps, tanks, filters, treatment equipment, and valves should feel familiar.
8. Practice open-book searches with permanent tabs.
9. Take 45-question practice sets.
10. Time full practice sessions at 90 minutes.

Study the Pump System as One Connected Water System

Strong specialty-plumber preparation is easier when you stop treating the pump as a lonely machine. Follow the water from the source through the pump, pressure tank, treatment or filtration equipment, valves, distribution piping, irrigation equipment, and point of use.

Ask what happens if pressure is too low, the tank is undersized, a valve is installed incorrectly, filtration creates excessive pressure loss, piping is too small, or the system creates a contamination risk.

Review the Washington Domestic Pump or Irrigation Specialty Plumber collection at 1ExamPrep for exam-focused preparation materials.

Because Washington also requires electrical certification for this trade, candidates moving toward the electrical side can review related Washington pump-and-irrigation electrical materials on 1ExamPrep, including the Washington Pump & Irrigation Master Electrician Book Package when that master-level electrical path becomes relevant.

For licensing support, review 1ExamPrep application services. For books, exam preparation, licensing expenses, and related professional costs, review 1ExamPrep financing options.

Frequently Asked Questions

Conclusion

Washington's Domestic Pump and Pump and Irrigation specialty plumbing program is unusual because the work sits directly between plumbing and electrical systems. A pump needs water piping, pressure control, tanks, treatment equipment, and valves, but it also needs motors, controls, conductors, disconnecting means, and other electrical equipment. Washington therefore requires the proper certification on both sides of the trade.

The plumbing side starts with choosing the correct specialty. PL03 Pump and Irrigation is the broader certification. It covers qualifying equipment used to acquire, treat, store, or move water suitable for drinking, domestic purposes, or irrigation. The standard PL03 experience requirement is at least two years and 4,000 hours in the specialty under the appropriate certified plumber.

PL03A Domestic Well is more limited. Current Washington rules limit its plumbing scope to qualifying limited-volume pumping systems not exceeding 100 gallons per minute. Labor & Industries also describes the domestic-well combination work with a pump limit of 7.5 horsepower, single phase. The standard plumbing experience requirement is at least one year and 2,000 hours under an appropriate certified plumber.

Experience has to be documented. Washington plumber trainees should make sure their affidavits of experience are on file with Labor & Industries before applying for the exam. Keep records of hours, dates, employers, supervising plumbers, and the kind of pump-system work performed.

The current PSI examination is called Domestic Pump or Irrigation Specialty Plumber. PSI's 2026-revised bulletin lists 45 questions, 90 minutes, a 70 percent passing score, and an open-book format. The approved pump-specialty plumbing reference is the 2015 Uniform Plumbing Code with Washington State Amendments.

Labor & Industries says the specialty exam draws from UPC Chapters 2, 3, 6, and 16. Chapter 2 covers definitions. Chapter 3 contains general plumbing requirements. Chapter 6 covers water supply and distribution, which is central to pump work. Chapter 16 covers alternate water-source provisions.

The open-book format can be helpful, but the pace is quick. Forty-five questions in 90 minutes gives you about two minutes per question. Practice finding definitions, water-supply rules, tables, exceptions, and specialty provisions without reading entire chapters during the test.

PSI currently allows the approved reference to contain highlighting, underlining, annotations, and permanent tabs prepared before the exam. Temporary tabs are not allowed, extra loose or attached papers are not allowed, and candidates may not write in the reference during testing.

The application process starts with Labor & Industries, not PSI. Candidates need Department approval before scheduling the plumbing examination. Approved eligibility is valid for one year. Labor & Industries currently says online examination application is not available for PL03 or PL03A, so candidates use the mail process.

Current fees are also worth planning for. Labor & Industries currently lists a $202.10 plumbing examination application fee. After passing, the current certification fee for Domestic Pump or Pump and Irrigation is $242.80. PSI separately charges its scheduling or exam fee, and the current bulletin lists $52 for an individual portion.

After passing, PSI states that successful candidates have 90 days to pay the certification fee. Miss that window and retesting may be required. If you fail the exam, Washington currently requires a 14-calendar-day waiting period before retesting.

Certification renewal is every three years on your birthday. The current renewal fee for PL03 and PL03A is $242.80, and the current late fee is another $242.80. The continuing-education requirement is 24 hours, split between at least 12 hours of electrical education and 12 hours of plumbing education in the approved categories.

A good preparation plan therefore has three parts. First, understand your specialty scope and make sure your experience is documented. Second, learn Chapters 2, 3, 6, and 16 of the 2015 UPC with Washington amendments. Third, treat electrical certification as a separate but necessary part of the career path.

Study the complete water system rather than just the pump. Understand how the source, pump, pressure tank, treatment equipment, valves, piping, controls, distribution system, and irrigation or domestic loads work together. That system-level knowledge will help on the exam and on the job.

Key Takeaways

• Washington separates pump plumbing into PL03 Pump and Irrigation and PL03A Domestic Well, with different scopes and experience requirements.
• PL03 currently requires at least 2 years / 4,000 hours, while PL03A requires at least 1 year / 2,000 hours of qualifying specialty experience.
• The current Domestic Pump or Irrigation Specialty Plumber exam has 45 questions, allows 90 minutes, requires 70 percent to pass, and is open book.
• The exam uses the 2015 Uniform Plumbing Code with Washington State Amendments and draws from Chapters 2, 3, 6, and 16.
• Washington also requires the proper electrical certification for pump and irrigation work, and PL03/PL03A plumber certificates renew every 3 years with 24 hours of mixed plumbing/electrical continuing education.

Plain-Language Summary

Washington has two main specialty plumbing certificates for pump work. PL03 is Pump and Irrigation. PL03A is Domestic Well. They are related, but they do not allow exactly the same work.

PL03 is the broader specialty. It covers qualifying equipment used to acquire, treat, store, or move water for drinking, other domestic purposes, or irrigation. This can include pumps, pressure tanks, storage tanks, treatment equipment, filtration equipment, valves, and related plumbing components.

To qualify for PL03, Washington currently requires at least 4,000 hours of work over at least two years. That experience must be in the specialty and under the proper certified plumber.

PL03A Domestic Well is more limited. Washington rules describe it as work on qualifying domestic pumping systems not exceeding 100 gallons per minute. Labor & Industries also describes the combination domestic-well trade with a pump limit of 7.5 horsepower, single phase.

To qualify for PL03A, you currently need at least 2,000 hours of qualifying specialty work over at least one year under the proper certified plumber.

Before you can test, your experience needs to be documented with Washington Labor & Industries. Plumber trainees should make sure their experience affidavits are already on file.

Pump and irrigation work also has an electrical side. Washington says workers doing pump and piping work on domestic water systems and irrigation systems need the appropriate plumbing and electrical certifications. Your PL03 or PL03A plumber card does not automatically give you electrical authority.

The current plumbing exam is called Domestic Pump or Irrigation Specialty Plumber. PSI's 2026 bulletin lists 45 questions, a 90-minute time limit, a 70 percent passing score, and an open-book format.

The approved reference is the 2015 Uniform Plumbing Code with Washington State Amendments. Labor & Industries says the exam questions come from Chapters 2, 3, 6, and 16.

Chapter 2 covers definitions. Chapter 3 covers general plumbing requirements. Chapter 6 covers water supply and distribution. Chapter 16 covers alternate water sources. Spend extra navigation time in Chapter 6 because water supply and pressure are central to pump-system work.

The exam is open book, but you only have about two minutes per question. PSI allows highlighting, underlining, annotations, and permanent tabs prepared before the exam. Temporary tabs are not allowed, and you cannot write in the reference during testing.

Apply to Labor & Industries before trying to schedule with PSI. L&I must approve your exam eligibility first. The Department currently says online exam application is not available for PL03 or PL03A, so use the mail application process.

Labor & Industries currently lists a $202.10 exam application fee. After you pass, the current certification fee for Domestic Pump or Pump and Irrigation is $242.80. PSI also charges its own exam scheduling fee.

Your plumber certificate renews every three years on your birthday. The current PL03/PL03A renewal fee is $242.80. Washington currently requires 24 hours of continuing education before renewal, including at least 12 hours of electrical education and 12 hours of plumbing education.

Use the Washington Domestic Pump or Irrigation Specialty Plumber collection from 1ExamPrep to organize your exam preparation around the 2015 UPC, Washington amendments, pump-system scope, water-supply rules, definitions, and open-book navigation.