100+ Free MN Plumber Practice Questions

Pass your Minnesota Journeyman Plumber License Exam exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately

~45-55% Pass Rate

100+ Questions

100% Free

1 / 100

Question 1

Score: 0/0

Per the MPC as adopted by Minnesota, what is the minimum slope for a 4-inch horizontal drain pipe?

1/16 inch per foot

1/8 inch per foot

1/4 inch per foot

1/2 inch per foot

to track

Same family resources

More Plumber License Prep

Continue through related practice pages, study guides, comparisons, and articles from the same exam family.

Practice Pages

Alabama Journeyman Plumber Practice100 questions Alaska Journeyman Plumber Practice100 questions Arizona Journeyman Plumber Practice100 questions Arkansas Journeyman Plumber Practice100 questions California Journeyman Plumber Practice100 questions Colorado Journeyman Plumber Practice100 questions

Free Journeyman Plumber Practice Test by State 2026: 4,700+ Questions24 min read

2026 Statistics

Key Facts: MN Plumber Exam

70%

Passing Score

MN Dept of Labor

240 pts

Exam Points

State exam format

5.5 hrs

Time Limit

Longest in US

MPC

Code Base

State-specific

The Minnesota journeyman plumber exam is administered by the Department of Labor and Industry as a paper exam. At 5.5 hours and 240 points, it is one of the longest plumbing exams in the nation. Minnesota uses its own Minnesota Plumbing Code (MPC) — neither IPC nor UPC. The exam requires 70% (168/240 points) to pass. Candidates must study the MPC specifically, as it has significant differences from national model codes.

Sample MN Plumber Practice Questions

Try these sample questions to test your MN Plumber exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Per the MPC as adopted by Minnesota, what is the minimum slope for a 4-inch horizontal drain pipe?

A.1/16 inch per foot

B.1/8 inch per foot

C.1/4 inch per foot

D.1/2 inch per foot

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific), horizontal drainage pipes 4 inches and larger require a minimum slope of 1/8 inch per foot. Pipes 3 inches or smaller require 1/4 inch per foot minimum slope.

2Per the MPC, what is the DFU value for a floor-mounted water closet (1.6 GPF)?

A.2 DFU

B.3 DFU

C.4 DFU

D.6 DFU

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific) fixture unit table, a floor-mounted water closet with a 1.6 GPF rating has a DFU value of 4. This is the standard value used for drainage system sizing.

3What is the minimum building drain size for a system with 200 DFUs per the MPC as adopted by Minnesota?

A.3 inches

B.4 inches

C.5 inches

D.6 inches

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific) drainage sizing tables, a 4-inch building drain at 1/8 inch per foot slope can handle up to approximately 216 DFUs, so 4 inches is adequate for 200 DFUs.

4Per the MPC, cleanouts in horizontal drains must be installed at intervals not exceeding what distance?

A.50 feet

B.75 feet

C.100 feet

D.125 feet

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific), cleanouts must be installed at maximum 100-foot intervals in horizontal drainage lines. They are also required at changes of direction and at the upper terminal of the building drain.

5Per the MPC, what is the minimum slope for a 2-inch horizontal drain pipe?

A.1/16 inch per foot

B.1/8 inch per foot

C.1/4 inch per foot

D.1/2 inch per foot

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific), horizontal drainage pipes 3 inches and smaller (including 2-inch) require a minimum slope of 1/4 inch per foot to maintain adequate flow velocity.

6Per the MPC as adopted by Minnesota, a lavatory has what DFU value?

A.0.5 DFU

B.1 DFU

C.1.5 DFU

D.2 DFU

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific) fixture unit table, a lavatory has a DFU value of 1. This is one of the lowest individual fixture DFU ratings.

7What is the minimum trap size for a kitchen sink per the MPC?

A.1-1/4 inches

B.1-1/2 inches

C.2 inches

D.3 inches

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific), the minimum trap and drain size for a kitchen sink is 1-1/2 inches.

8Per the MPC, what fitting is required for a horizontal-to-horizontal direction change in drainage piping?

A.Short-sweep quarter bend

B.Long-sweep quarter bend or equivalent

C.Standard tee fitting

D.Any available fitting

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific), horizontal-to-horizontal changes of direction must use long-sweep fittings. Short-sweep fittings are restricted to horizontal-to-vertical transitions.

9Per the MPC, indirect waste from a commercial dishwasher must discharge through what?

A.A direct connection to the building drain

B.An air gap to an approved receptor

C.A check valve

D.A backwater valve

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific), indirect waste from commercial food equipment must discharge through an air gap into an approved floor sink or receptor to prevent contamination.

10Per the MPC, what is the maximum DFU load on a 3-inch horizontal branch at 1/4 inch per foot slope?

A.20 DFU

B.27 DFU

C.36 DFU

D.42 DFU

Explanation: Per the Minnesota Plumbing Code (MPC, state-specific) drainage table, a 3-inch horizontal branch at 1/4 inch per foot slope handles a maximum of 36 DFUs.

About the MN Plumber Exam

Minnesota journeyman plumber licensing exam administered by the Department of Labor and Industry. State-administered paper exam based on the Minnesota Plumbing Code (MPC), a completely state-specific plumbing code — not IPC or UPC. The exam is 240 points over 5.5 hours, making it one of the longest plumbing exams in the country. Requires 70% (168 points) to pass.

Questions

120 scored questions

Time Limit

5.5 hours

Passing Score

70%

Exam Fee

~$250 (Minnesota Department of Labor and Industry)

MN Plumber Exam Content Outline

25%

Drainage Systems

Drain pipe sizing, fixture unit calculations, slope requirements, cleanouts, building sewers, indirect waste, and special drainage per Minnesota Plumbing Code

20%

Water Supply Systems

Water pipe sizing, fixture unit calculations, backflow prevention, pressure regulation, water heaters, cross-connection control per MPC

20%

Venting Systems

Vent sizing, wet venting, circuit venting, air admittance valves, vent termination, combination waste and vent per Minnesota code

15%

Fixtures & Appliances

Fixture installation, clearances, accessible fixtures, commercial fixtures, water closets, lavatories, showers, and bathtubs per MPC

10%

Code Administration & Minnesota Regulations

Minnesota plumbing licensing rules, permits, inspections, plan review, and MPC-specific administrative requirements

10%

Materials, Joints & Special Systems

Approved materials, pipe materials, joint methods, hangers and supports, medical gas, storm drainage, and sewage ejectors per MPC

How to Pass the MN Plumber Exam

What You Need to Know

Passing score: 70%
Exam length: 120 questions
Time limit: 5.5 hours
Exam fee: ~$250

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

MN Plumber Study Tips from Top Performers

1Study the Minnesota Plumbing Code (MPC) exclusively — it is NOT based on IPC or UPC and has unique requirements

2Practice time management for the 5.5-hour exam — allocate time proportionally to each section's point value

3Master fixture unit calculations per MPC — values and sizing methods differ from IPC/UPC

4Review MPC venting requirements carefully — wet venting and circuit venting rules are state-specific

5Study Minnesota-specific regulations on materials, inspections, and licensing requirements

6Practice drain pipe sizing using MPC tables and slope requirements

7Review backflow prevention and cross-connection control per Minnesota regulations

8Take full-length timed practice exams to build stamina for the 5.5-hour test duration

Frequently Asked Questions

How hard is the Minnesota journeyman plumber exam?

The Minnesota journeyman plumber exam is one of the most challenging in the country with an estimated 45-55% pass rate. At 240 points over 5.5 hours, it is also one of the longest. Minnesota uses its own state-specific plumbing code (MPC), not the IPC or UPC, which means code books and study materials from other states do not apply.

What plumbing code does Minnesota use?

Minnesota uses the Minnesota Plumbing Code (MPC), a completely state-specific plumbing code. It is NOT based on the IPC or UPC. The MPC has unique requirements for drainage, venting, water supply, and fixtures that differ significantly from national model codes. Candidates must study the MPC specifically.

Why is the Minnesota plumber exam 5.5 hours?

Minnesota's 5.5-hour exam with 240 points is one of the longest plumbing exams in the nation. The extended time reflects the comprehensive nature of the exam, which covers all aspects of the Minnesota Plumbing Code in depth. The paper format also requires more time than computer-based exams. Pacing is critical — allocate time proportionally across sections.

How much does the Minnesota plumber exam cost?

The Minnesota journeyman plumber exam fee is approximately $250. Additional costs include the Minnesota Plumbing Code book. Check with the Minnesota Department of Labor and Industry for the current fee schedule and exam dates.