Delaware licenses plumbers at a single level: the Master Plumber license, issued by examination through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners in the Division of Professional Regulation. There is no Delaware journeyman license. The PassProfessor Delaware Master Plumber program prepares candidates for the single Prov examination — 100 questions in 180 minutes, open book, 70 percent to pass — tested on the 2018 International Plumbing Code and the 2018 International Fuel Gas Code.
This program is part of the expanding PassProfessor catalog — join the notify list and we’ll email you when enrollment opens.
What this credential certifies
The Delaware Master Plumber license is the state’s only plumbing license, and that single fact shapes everything about preparing for it. In most states a candidate climbs an examined ladder — a journeyman examination first, a master examination later — and preparation can be staged across two sittings. Delaware does not work that way. The Journeyman’s Certificate a Delaware apprentice earns is a credential of apprenticeship completion, issued against a program meeting or exceeding the Federal Bureau of Apprenticeship and Training Standards; it is not a state license, and it is not examined by Prov. The license itself, the one that authorises a plumber to practise at the examined level in Delaware, is the Master Plumber license, and it is obtained by examination only.
That means the Delaware sitting carries the whole trade at once. The candidate who sits for it is not being tested on a supervised worker’s subset of the craft; the examination assumes a practitioner ready to take responsibility for complete plumbing and fuel gas work — sizing, design judgement, code application, safety — in a state with no second examined step waiting behind it.
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Delaware Master Plumber: the single examined plumbing license in Delaware |
| Regulator | Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, within the Division of Professional Regulation (DPR), under 24 Del.C. ch. 18 and 24 DE Admin. Code 1800 |
| Examination vendor | Prov, Inc. (ProV), under contract with the Board; Board approval precedes Prov registration |
| Examination structure | A single examination. There is no separate Business and Law portion and no Business and Law content area |
| Format | 100 questions / 180 minutes / open book / computer-based |
| Passing standard | 70% to pass, as stated in the Prov Candidate Information Bulletin header |
| Examination fee | $100.00, paid to Prov at registration (bulletin layer) |
| Tested references | International Plumbing Code 2018 and International Fuel Gas Code 2018, both open-book references |
| Adopted code | 2021 State of Delaware Plumbing Code (2021 IPC with Delaware amendments) — one edition ahead of the tested edition |
| Administrator note | PassProfessor is independent and is not affiliated with the Board or the Division of Professional Regulation |
One examination, not two
Candidates researching Delaware online will encounter an older description of a two-part examination with a separate Business and Law portion, administered by a different vendor. That description is stale and it is barred from this page for good reason: the bulletin of record — Prov’s Delaware Division of Professional Regulation — Candidate Information Bulletin, document DE CIB 2026.10.31, Version 1.0, effective October 31, 2026 — describes one examination and one only. The content outline totals 100 questions across ten trade areas, and no Business and Law area appears in it. Delaware preparation begins by discarding the two-part picture completely.
The single examination is computer-based. It is delivered at two Prov computer-based testing centres in Delaware — Dover and Wilmington, per the bulletin — or remotely through Examroom.ai proctoring, and it is offered in English. Board approval comes first in the sequence: the Division of Professional Regulation forwards approved registrations to Prov, and only then does the candidate register and pay the $100.00 examination fee to Prov.
What the examination covers
The Prov outline distributes its 100 questions as follows, and the distribution is itself a study plan. General Knowledge carries 16 questions, the largest single block. Drain, Waste and Vent Systems and Water Supply and Distribution carry 14 each — together with general knowledge, the traditional core of the craft accounts for 44 of the 100 questions. Water Heaters and Fuel Gas Systems carry 10 each, a weighting that tells fuel gas candidates plainly that gas is not a minor annex to this license: a fifth of the sitting, counting the fuel gas code book’s share of the general areas, turns on work governed by the second reference on the table. Isometrics and Plan Reading, Plumbing Math, and Fixtures and Fittings carry 8 each. Storm and Roof Drainage and Safety close the outline at 6 each.
One feature of that outline deserves emphasis. Isometrics and Plan Reading is a written content area inside a computer-based examination — eight questions that test whether the candidate can read and reason from drawings. There is no separate drawing examination and no hands-on practical described for the Prov Master Plumber examination in the sources; the drawing skill is examined on screen, as questions.
Tested on 2018, working under 2021: the edition split
Delaware’s code layers are the state’s defining examination trap, and this program is built around it. The references open on the candidate’s desk are the International Plumbing Code 2018 and the International Fuel Gas Code 2018 — both are listed as open-book references in section 5.9 of the Prov bulletin. Plumbing Basics for Contractors, 3rd Edition, 2014, appears in the bulletin as study material only; it is not an open-book reference and cannot be taken into the sitting as one.
The code Delaware has adopted for actual work is a different, newer book: the 2021 State of Delaware Plumbing Code, the 2021 IPC with Delaware amendments, at 16 DE Admin. Code 4455, effective August 11, 2022. The tested edition is one edition behind the adopted edition. No Delaware amendment is an examination reference. The practical consequence is exact: where the 2018 and 2021 editions differ, the sitting credits the 2018 answer, and the job site demands the 2021 rule. A candidate who studies only from the code book currently in the truck will answer some questions the way Delaware law now requires the work to be done — and score them wrong. This program teaches the tested layer as the tested layer, flags the split wherever the two editions part company, and never presents the adopted code as examination material.
The routes to eligibility
Board approval is required before sitting, and Delaware recognises two experience routes beneath it. The first route runs through apprenticeship: the candidate holds a Journeyman’s Certificate from an apprenticeship program meeting or exceeding the Federal Bureau of Apprenticeship and Training Standards, and then completes two years of verified experience under the supervision of a licensed plumber or master plumber.
The second route is the long-experience route: seven years of verified experience under the supervision of a licensed plumber or master plumber, together with the apprenticeship-equivalency testing route the Board requires for candidates who did not complete a certificate program. The statute, the Board’s regulations, and the Division’s published pages describe that testing instrument in different terms — candidates on this route should confirm the current instrument and its administrator with the Board directly rather than rely on any single description, including secondary summaries. For some applicants on the non-certificate route, the Board requires the Apprenticeship-By-pass examination, administered by Associated Builders and Contractors Delaware, as a prerequisite gate before the Prov examination. That gate is not part of the Prov examination itself, and its pass mark, format, fee, question count, time limit, and references are not stated on the Division’s examinations page — this page states none of them, and candidates subject to the gate should obtain its particulars from the Board.
Beyond experience, the statute sets character and standing bars: an applicant must hold a passing examination score and must not carry the disqualifying administrative penalties, impairment, pending discipline or complaints, substantially related convictions, or felony sexual-offence convictions the statute lists, subject to the Board’s waiver provisions. Reciprocity exists but is conditional: section 1810 addresses applicants holding a current license in good standing in a jurisdiction whose standards are substantially similar to Delaware’s, with a statutory fallback for applicants licensed seven years in a jurisdiction whose standards are not substantially similar. The Board makes that determination.
Retakes, stated in their layers
Delaware’s retake rules live in three layers, and the layers are not identical, so this page keeps them separate. The Prov bulletin layer provides for up to three attempts on a single approval, with a minimum seven-day wait before retesting, after which the candidate reapplies to the licensing authority; a passed examination may not be retaken unless the authority requires it, and results are graded immediately and forwarded to the authority. The regulation layer provides for two additional retakes without further Board approval, and states that after three failed attempts the applicant must reapply and may not reapply until one year has passed from the last attempt. The statute layer states that the examination must be offered at least quarterly and that a failing applicant may apply to retake on the next available date.
Staying licensed: renewal and continuing education
The Master Plumber license is biennial, expiring October 31 of even-numbered years. Continuing education is required — any source claiming Delaware has no continuing education requirement for this license is stale. Licensees complete five hours of approved continuing education during each renewal period: three hours on code changes, one hour on safety, and, for plumbing licensees, one hour on cross connections and back flow. A licensee holding both plumbing and HVACR licenses completes six total hours. The hours are completed by October 31 of even-numbered years, beginning in 2026; there is no carryover; completion is attested at renewal, and the Division audits a random five percent of renewals and all late renewals. Late renewal remains available for up to one year after expiration, and inactive status may be held for up to five years.
What the PassProfessor program will cover
The whole trade in one sitting, because Delaware examines it that way. The program is organised on the Prov outline’s own weights: the 44-question core of general knowledge, drainage, waste and venting, and water supply first; fuel gas and water heaters at their full combined weight next; then isometrics and plan reading, plumbing math, fixtures, storm drainage, and safety as examined skills rather than afterthoughts.
The 2018 books as the examination’s law. Every practice item is keyed to the 2018 IPC and the 2018 IFGC — the editions open on the desk — and the adopted 2021 Delaware code is taught as context and contrast, never as the source of a credited answer. Where the editions differ, the program says so in terms, so the candidate learns both the answer the sitting wants and the rule the work will be inspected under.
Delaware’s single-license structure, taught plainly. The program covers the Board and Division framework under 24 Del.C. chapter 18 and 24 DE Admin. Code 1800, the two eligibility routes and the by-pass gate that stands in front of some candidates, the layered retake rules, and the renewal and continuing education cycle.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, the Division of Professional Regulation, or Prov. Completing this program confers no license and no eligibility; the Board alone approves candidates and issues licenses, and candidates register for the examination through Prov after Board approval. The companion Delaware Master Plumber Exam Guide works through the credential, the outline, and the study method in full.
Tell me when enrollment opens. The Delaware Master Plumber program is in the works as our catalog continues to expand into the plumbing trades, and enrollment is not yet open. Leave an email address and PassProfessor will write to you when the program is ready — and only about this program. No date is promised, because the program will open when it meets the standard described above, not before.
Frequently asked questions
Does Delaware have a journeyman plumber license?
No. Master Plumber is Delaware’s only plumbing license, issued by examination. The Delaware Journeyman’s Certificate is an apprenticeship-completion credential, not a state license, and it is not examined by Prov.
How many examinations must a Delaware Master Plumber candidate pass?
One. The Prov examination is a single examination of 100 questions in 180 minutes. There is no separate Business and Law portion and no Business and Law content area. Older descriptions of a two-part examination are stale.
What score passes the Delaware Master Plumber examination?
70% to pass, as stated in the Prov Candidate Information Bulletin. The figure is a bulletin-layer standard; the Board’s regulations state no numeric passing score for plumbing.
Is the Delaware examination open book?
Yes. The International Plumbing Code 2018 and the International Fuel Gas Code 2018 are the open-book references.
Which code edition is tested, and which is adopted?
Tested: the 2018 IPC and the 2018 IFGC. Adopted for work in Delaware: the 2021 State of Delaware Plumbing Code, the 2021 IPC with Delaware amendments. The tested edition is one edition behind the adopted edition, and candidates are examined on the 2018 editions.
What does the examination cost?
The examination fee stated in the Prov bulletin is $100.00, paid to Prov at registration. Division of Professional Regulation licensure fee amounts are not printed on this page; take current amounts from the Division.
Is there a practical or drawing examination?
No hands-on practical and no separate drawing examination is described for the Prov Master Plumber examination. Isometrics and Plan Reading is a written content area of eight questions inside the single computer-based examination. Some candidates on the non-certificate route must first pass the separate Apprenticeship-By-pass examination as a Board prerequisite gate; that gate is not part of the Prov examination.
What experience does Delaware require?
Either a Journeyman’s Certificate from a qualifying apprenticeship program followed by two years of verified experience under a licensed or master plumber, or seven years of verified experience under a licensed or master plumber together with the Board’s apprenticeship-equivalency testing route. Board approval is required before sitting.
What happens after a failed attempt?
Under the Prov bulletin, up to three attempts are permitted on a single approval with a minimum seven-day wait before retesting. Under the Board’s regulations, after three failed attempts the applicant must reapply and may not reapply until one year has passed from the last attempt.
What continuing education does renewal require?
Five hours of approved continuing education per renewal period for plumbing licensees — three hours of code changes, one hour of safety, and one hour on cross connections and back flow — completed by October 31 of even-numbered years. The license is biennial.
Is PassProfessor affiliated with the Delaware Board or the Division of Professional Regulation?
No. PassProfessor is an independent preparation provider. The Board alone approves candidates and issues licenses.
When does enrollment open?
The program is in the works and enrollment is not yet open. Leave an email address on this page and PassProfessor will write to you when the program is ready — and only about this program.