The New Hampshire Master Plumber Guide

Facts in this guide are drawn from the Prov, Inc. Candidate Information Bulletin for the New Hampshire Mechanical Board (NH Mechanical (Plumbing) CIB 2025.06.23), published by the OPLC and read on September 30, 2026, and from the state law that adopts the plumbing code — RSA 155-A:1, IV, effective July 1, 2026. New Hampshire rules and bulletins change: always confirm against the current bulletin and the Board before you apply.

What Is the New Hampshire Master Plumber License?

In New Hampshire, plumbing licensure belongs to the Mechanical Board within the Office of Professional Licensure and Certification (OPLC). The Board publishes its licensing rules as the Mec rules — including the part headed Eligibility and Examination for Plumbing, Fuel Gas Fitting, Domestic Appliance, and Hearth Licensure — and those rules publish the eligibility, the fees, the licence durations and the training programmes, and reference the state plumbing code. They do not publish the examination format. What the exam contains is published by the candidate bulletin, which the OPLC hosts on its own domain and which the vendor Prov, Inc. produces.

That division matters when you research your own path, because a candidate who reads only the rules learns that the examination exists and nothing about its size. And there is a second division inside the bulletin itself, worth understanding before you study: it publishes three plumbing blocks — Master Plumber (100 questions, 3 hours, eight subject areas), Journeyman Plumber (85 questions, 3 hours) and First Year Plumbing Apprentice (100 questions, 3.33 hours). They are separate examinations, and their subject areas are suffixed with the level in the bulletin — Master Plumber, Journey Level — so the two are easy to tell apart once you know to look. This guide is built on the Master Plumber block, because that is the credential this platform prepares you for.

The Code the State Adopted, and the Edition the Bulletin Still Lists

New Hampshire is one of the states where the code of the state and the reference list of the examination bulletin have not moved at the same time. Both facts are published; here they are side by side.

• The state code is the 2024 edition. RSA 155-A:1, IV defines the state building code as the adoption by reference of the International Plumbing Code 2024, among the other codes it lists, with the source of the act effective July 1, 2026. The Board references the state plumbing code in its own rules.
• The bulletin in force still lists the 2018 edition. The approved references printed with the plumbing blocks name the International Plumbing Code 2018, with its ISBN, alongside the Board's administrative rules.

That is the exam's edition lag, published. What it means for your preparation: read the bulletin you receive and treat the edition it lists as the edition the form is built from — and note the reference rule that runs the other way, which allows older or newer editions of a reference to be brought to the session, provided the book title is exact. So the edition moves first in the reference list and later in the questions; when the bulletin is revised, the subject areas and their weights stay exactly where they are and only the editions move.

Exam Format: Open Book, 100 Questions, 3 Hours, 70%

The New Hampshire Master Plumber examination is computer-based and delivered by the vendor under the OPLC bulletin. At a glance:

Three details deserve to be read twice. First, the references are optional to buy but costly to leave at home: the bulletin states that it is not mandatory that candidates purchase study materials, but that all examinations permit the use of authorized study materials and that candidates may be at a disadvantage if they do not bring those materials with them to their testing session. Second, the bulletin recommends studying the references themselves, not only the code: it advises candidates to familiarise themselves with the exam references with emphasis on the subject areas listed in each exam description, because candidates who are familiar with their reference materials spend less time searching for answers during the exam. Third, the clock does not stop for a restroom break — if you leave the testing room you must notify your proctor, and the lost time cannot be recovered.

Official Content Outline: The Eight Master Plumber Subject Areas

The bulletin publishes the Master Plumber block with its subject areas and question counts. The eight areas sum exactly to 100:

Subject area names and question counts as published in the vendor's candidate information bulletin for the New Hampshire Mechanical Board (Master Plumber block).

The shape of this outline is unusually even, and it tells you how to plan. Four areas carry 15 questions each — Calculations, Drainage Requirements, Scope and Administration, and Venting Regulations — and four carry 10: Fixtures and Faucets, Plumbing and Fundamentals, Traps and Interceptors, and Water Distribution. There is no dominant block and no throwaway block: every area is worth between a tenth and a seventh of the paper. Two consequences follow. First, this is an outline that punishes skipping — a candidate who ignores scope and administration because it feels like paperwork gives away 15 questions before starting. Second, Calculations is tied for the largest single area at 15 questions, which is why the reference rules matter as much as the theory: your formula sheet cannot be added to a book, so the maths has to be practised rather than collected.

The Reference Rules: How to Prepare the Books You Bring

New Hampshire is an open-book examination, and the bulletin publishes a detailed set of reference rules for open book exams. They are worth reading as a checklist before exam day, because the proctor checks your materials against them:

• Exact titles: the book title must be exact — and the bulletin grants an exception that matters: older or newer editions are always permitted, and substitutes are allowed if listed in the exam details.
• Photocopies: photocopied versions of a reference book are only permitted when stated in the exam details.
• Tabs: permanent tabs such as gummed tabs, self-adhesive tabs with printable inserts, or insertable tab dividers (for three-ring binders only) are permitted. Moveable items such as repositionable tabs or Post-it notes are not permitted in a reference book.
• Marking: books can have highlighting and underlining in pen only, but you cannot mark in your books during the test. Candidates are encouraged to prepare their test materials by highlighting text or placing permanent tabs on important pages.
• Notes: handwritten notes are not allowed in any portion of a reference book unless authorized by your licensing or certifying jurisdiction.
• Nothing added: other documents (such as formula sheets or the commercial code indexes candidates often carry) or stickers cannot be added, glued or taped to a reference book.
• Bring them: it is not mandatory to purchase study materials, but all examinations permit the use of authorized study materials, and candidates may be at a disadvantage if they do not bring those materials with them. At a minimum, the bulletin recommends candidates have their own code books related to their exam.

Practical consequences for your preparation: acquire the approved references early and prepare them in pen and permanent tabs — the rules leave no room for a pencil-annotated book, a sticky-tabbed book, or a book with your formula sheet taped inside. Then rehearse finding answers in exactly that set, because the bulletin says plainly that familiarity with the references is the skill that saves time under the clock.

Results, Review and Challenge: What Happens After You Sit

• Results: you receive your unofficial written results by email within minutes of completing your exam, and official results are sent to the State within 3 business days. Because the examination process is a requirement for licensure with the OPLC, candidates automatically consent to permit the vendor to share their test results with the State.
• Passed once, done: candidates cannot retake an exam once they have passed that exam unless required by the New Hampshire OPLC.
• Review: a review lets you audit your testing results by seeing which questions you missed. Candidates may request one after failing an exam category two times, and only where they scored within 10% of the required passing score. The review runs 1-1/2 hours, under the same testing conditions and security rules as the exam, with a printout of the missed questions and the answers chosen, and it costs $90.00 including tax for each test reviewed.
• Challenging a question: if you encounter a question you believe is inaccurate, you can submit an Exam Comment form to the vendor; candidates testing on computer may make their comments in the testing system, and candidates reviewing an exam are provided with an Exam Comment form. The vendor reviews each comment within two weeks of receipt and makes scoring adjustments should any comment result in a change to a test question.
• Hand score: if you want your score reassessed for accuracy, you can request a Hand Score by calling the vendor and asking for the Hand Score Request Form. The form requires a signature and must be mailed; it must be received no later than 90 days after your examination administration date and must be accompanied by a copy of your original score letter. Requests are processed within seven to ten business days.
• Accommodations: the vendor complies with the Americans with Disabilities Act in providing accommodations, which are requested with the vendor's ADA forms and supported by written documentation from a licensed physician or psychologist.

How to Prepare

1. Read the bulletin you receive for the code edition. The state adopted the IPC 2024 (RSA 155-A:1, IV, effective July 1, 2026) while the bulletin in force still lists the IPC 2018. The edition named in your bulletin is the one to prepare.
2. Build your reference set to the rules before you build anything else. Exact titles, pen-only highlighting and underlining, permanent tabs, no Post-it notes, no handwritten notes, no added sheets or stickers.
3. Drill all eight areas. Four areas at 15 questions and four at 10 — there is no area you can afford to skip. Practice questions should mirror those weights, and Scope and Administration deserves its own block.
4. Practise calculations with the book open. Calculations is tied for the largest area at 15 questions, and no formula sheet may be added to a reference book: the maths has to be at your fingertips, not in your notes.
5. Rehearse the reference lookup itself. The bulletin recommends familiarising yourself with the exam references with emphasis on the subject areas in the exam description, because candidates who know their references spend less time searching during the exam.
6. Simulate the real session. Full-length, timed runs of 100 questions in 3 hours, open book with your prepared references, aiming comfortably above the 70% line. MasterPlumberPractice reproduces the New Hampshire format in a full-length simulation so the real examination feels like a repeat.

MasterPlumberPractice is built for exactly this examination: practice questions aligned to the New Hampshire blueprint, theory covering the IPC code the state has adopted, full-length timed simulations in the published format, and an AI tutor to close your weak areas. Start with free practice questions to feel the format, work through our plumbing code theory guides, and create a free account to track your scores as you go.

Frequently Asked Questions

Ready to Earn the New Hampshire Master License?

New Hampshire is an evenly weighted examination — four areas at 15 questions and four at 10 — taken open book with a reference set you prepare to a published rulebook of your own. There is no area to skip and no formula sheet to smuggle in. Confirm the edition in force with the Board, prepare your references properly, then build your prep around the published blueprint: study the code with our plumbing code theory guides, try free practice questions, register free and see the all-inclusive pricing — one subscription covering the full New Hampshire blueprint, so you never buy prep piece by piece.