Idaho Plumbing Specialty Appliance Journeyman Exam

Idaho Plumbing Specialty Appliance Journeyman Exam: 2026 Study Guide

If you're working toward your Idaho appliance journeyman plumber license, this exam is the gateway. Passing the Idaho plumbing specialty appliance journeyman exam authorizes you to perform appliance-related plumbing work in one- and two-family residences — a focused but valuable credential. The exam is 50 questions, open book, and very passable with the right prep. This guide covers exactly what's on it, what to study first, and how to walk in ready.

Exam Overview

The Idaho Plumbing Specialty Appliance Journeyman exam is administered by PSI on behalf of the Idaho Division of Occupational and Professional Licenses (state licensing website). Here's the format at a glance:

• Questions: 50 scored questions
• Time limit: 150 minutes (2.5 hours)
• Passing score: 75% — that's 38 of 50 questions correct
• Format: Open book (your code book is your lifeline)
• Delivery: Computer-based at PSI testing centers

Your score appears on screen the moment you finish. The official exam bulletin has everything else you need to know about scheduling and testing-center policies.

Topics Covered on the Idaho Specialty Plumbing Journeyman Exam

All 50 questions are drawn from six chapters of the 2017 Idaho State Plumbing Code. Here's how the exam is weighted — and where to put your energy:

Chapter 5 — Water Heaters (20 items)

This is nearly 40% of the entire exam. Focus here first. You'll need to know water heater placement rules (bedrooms, garages, attics, roofs), TPR valve and safety shutoff requirements, combustion air calculations, and venting system selection. Don't skim this chapter.

Chapter 1 — Administration (7 items)

Scope, permits, AHJ authority, permit validity and revocation, and exempt work. Straightforward if you read the chapter carefully.

Chapter 3 — General Regulations (7 items)

Material standards, pipe protection, pipe support intervals (Tables 313.3 and 313.6), and the approval process for alternative methods. Know your support spacing by material type.

Chapter 2 — Definitions (6 items)

These questions test precise terminology: drainage and venting terms, backflow and cross-connection vocabulary, water supply terms, and trap-related definitions. Exact wording matters here.

Chapter 6 — Water Supply and Distribution (5 items)

Backflow prevention device selection (air gap, AVB, PVB, RP, DC, etc.), cross-connection control, pipe joining methods, pressure regulators, and expansion tanks.

Chapter 12 — Fuel Gas Piping (5 items)

Gas piping materials, sizing methods (longest length, branch length, hybrid pressure), installation requirements, and pressure testing. Know how to read the gas-sizing tables.

Sample Questions

These are representative questions from the Idaho Plumbing Specialty Appliance Journeyman exam. Can you answer them? Try before you look — then take our free practice exam to see how you stack up.

Question 1 (Chapter 5 — Easy)
What are the minimum dimensions of the level working platform required in front of the service side of a water heater installed in an attic?
- A) 24 inches by 30 inches
- B) 24 inches by 24 inches
- C) 30 inches by 30 inches
- D) 30 inches by 36 inches

Question 2 (Chapter 5 — Medium)
When combustion air is provided by a mechanical air supply system, at what minimum rate must outdoor air be supplied per 1000 Btu/h for appliances in the space?
- A) 1.00 cubic feet per minute
- B) 0.35 cubic feet per minute
- C) 0.50 cubic feet per minute
- D) 0.25 cubic feet per minute

Question 3 (Chapter 1 — Medium)
Under the 2017 Idaho State Plumbing Code, the Board of Appeals is empowered to waive requirements of the code when circumstances warrant.
- A) True
- B) False

Question 4 (Chapter 12 — Medium)
What is the minimum size of section A (the main leaving the meter)? (Figure GB-7)
- A) 2-1/2 inch
- B) 1-1/2 inch
- C) 1-1/4 inch
- D) 1 inch

Question 5 (Chapter 3 — Medium)
You are installing a building drainage system and need to run a 4-inch sewer line parallel to a building's foundation footing. The trench will be deeper than the footing. According to the 2017 ISPC, at what minimum angle from the bottom exterior edge of the footing must the trench be located?
- A) 30 degrees
- B) 90 degrees
- C) 60 degrees
- D) 45 degrees

The correct answers aren't here — that's intentional. Work through them with your code book, then take the free practice exam to get immediate feedback.

What Types of Questions to Expect

Our full practice bank for this exam includes 255 questions across all six tested chapters. Here's what each topic area actually tests:

• Chapter 1 (28 practice questions): Permit procedural questions, AHJ authority and liability scenarios, and what work qualifies for exemptions. Expect situational questions like "is a permit required for this job?"
• Chapter 2 (24 practice questions): Definition-matching and application. You may be given a scenario and asked to identify the correct code term, or given a term and asked to distinguish it from a similar one.
• Chapter 3 (28 practice questions): Material approval, pipe protection scenarios (corrosion, freezing, fire-resistance), and support spacing lookups from Tables 313.3 and 313.6. Expect to use those tables.
• Chapter 5 (102 practice questions): The largest section — and rightfully so. Questions cover attic/garage/bedroom installation requirements, TPR valve specs, combustion air method selection, minimum CFM calculations, and venting system type selection. Expect a mix of straightforward recall and calculation-based questions.
• Chapter 6 (36 practice questions): Backflow preventer selection for specific hazard levels, prohibited connections, pipe material and joining method pairing, and expansion tank and pressure regulator requirements.
• Chapter 12 (37 practice questions): Gas pipe material identification, reading sizing tables using the longest-length or branch-length method, underground vs. aboveground installation rules, and pressure test specifications.

Start your free attempt with our free practice exam — 10 questions, no account needed. When you're ready to prep seriously, the full practice exam mirrors the real test exactly: 50 questions, 150-minute timer, and a score breakdown by topic so you know exactly where to focus.

Required Study Materials

This is an open-book exam, so your code book isn't optional — it's your primary tool.

Required Reference Book:
2017 Idaho State Plumbing Code (2017 ISPC) — This is the primary reference you'll use in the exam room. Every question on the Idaho DOPL appliance journeyman PSI exam is rooted in this code. You may also bring the 2015 Uniform Plumbing Code (UPC), ISBN-13: 9781938936647, but the 2017 ISPC is the Idaho-specific edition and the better choice.

How to prepare your book:
- Pre-highlight key sections: water heater installation (Chapter 5), pipe support tables (Chapter 3), backflow device requirements (Chapter 6), and gas sizing tables (Chapter 12)
- Tab every chapter and major table — physical tabs, not Post-its (Post-its are confiscated on exam day)
- Mark the index: you'll use it constantly under time pressure

No writing in the book during the exam. Highlighting and underlining before the exam is fine.

Study Tips for the Idaho Appliance Journeyman Plumber Test

Speed in the book beats memorization. On an open-book exam, the candidates who pass fastest aren't the ones who memorized everything — they're the ones who can land on any code section in seconds. Build that skill deliberately. Know your index and table of contents cold.

Work through questions in two passes. Answer what you know, skip what you don't, bookmark flagged questions. Then return to the hard ones. Don't let a single difficult question eat five minutes while easier ones wait.

Give yourself three to six weeks. Use the official exam bulletin as your study roadmap. Spend your energy on finding-it-fast skills, not memorizing code verbatim. Aim for 80%+ on practice tests before you schedule — that margin above the 75% cut score is your buffer.

Practice under the clock. Our timed full practice exam replicates the 150-minute pressure of the real thing. Do at least a few timed sessions before test day so the format feels routine, not stressful.

Prioritize Chapter 5. With 20 of 50 exam items, it's 40% of your score. Master water heater rules before you put serious time into any other chapter.

Frequently Asked Questions

How many questions are on the Idaho Plumbing Specialty Appliance Journeyman exam?
The exam has 50 scored questions.

What is the passing score?
You need 75% — that's 38 of 50 questions correct. Your score appears on screen as soon as you finish at the PSI testing center.

How much time do I have?
150 minutes (2.5 hours) for the full exam.

How much does it cost?
The exam fee is $75.00. Fees are non-refundable and non-transferable, but are valid for one year from the date of payment.

How do I register?
Register online at the exam registration page — available 24/7 — or call PSI at 855-340-3713 during their hours of operation.

Is the Idaho Plumbing Specialty Appliance Journeyman exam open book?
Yes. You may bring either the 2015 Uniform Plumbing Code (UPC) or the 2017 Idaho State Plumbing Code (2017 ISPC). No other references are permitted.

Can I write in my book during the exam?
No. Pre-exam highlighting and underlining are allowed, but no writing during the exam session. Post-its and additional papers will be confiscated.

What topics are covered?
Chapters 1, 2, 3, 5, 6, and 12 of the 2017 Idaho State Plumbing Code — totaling 50 exam questions.

What if I fail? Can I retake it?
Yes, you can retake the exam as many times as needed. Each attempt requires a new exam fee.

What ID do I need?
One government-issued photo ID with your name, signature, and photo — driver's license, state ID, U.S. passport, military ID, or alien registration card. Temporary IDs are only accepted when accompanied by the original expired ID.

Ready to Start?

The Idaho plumbing specialty appliance journeyman exam is achievable. Fifty questions, open book, and a clear code reference — the structure is on your side. Get your 2017 Idaho State Plumbing Code tabbed and highlighted, spend serious time on Chapter 5, and test your knowledge before exam day.

Start now with our free practice exam — 10 questions, no signup required. When you're ready to go deep, upgrade to the full practice exam for a complete timed simulation with topic-by-topic scoring. You've got this.