ICC F32 Residential Mechanical (Class C) (2015 IRC) Exam Study Guide
This guide covers what you need for the ICC F32 Residential Mechanical (Class C) (2015 IRC) exam: the key facts from the official bulletin, the topics it tests, the reference books, sample questions with answers, and a plan to prepare. Pearson VUE gives the exam.
ICC F32 Residential Mechanical (Class C) (2015 IRC) Exam at a Glance
Here are the exam's key facts from the official bulletin:
| Questions | 70 questions |
| Time limit | 3 hours |
| Passing score | a minimum score of 70 |
| Books in the exam room | Open book |
| Exam fee | $120 |
On exam day
- The exam consists of multiple-choice questions in four-option format with one scored correct answer.
References you may bring
- International Residential Code (2015)
Scheduling, changes and retakes
- Exams are scheduled through PearsonVUE at www.pearsonvue.com/ICC, where candidates can create an account, schedule an exam, locate a test center, purchase vouchers and request accommodations.
- Results for examinations taken electronically are available immediately after the examination is completed.
- You must wait 10 days before retaking a failed exam.
- After passing, contact the jurisdiction in which you wish to be licensed for any other requirements, because ICC is not a licensing agency.
Source: National Contractor/Trades Examination Information Bulletin, PUBLISHED June 30, 2026. Check the bulletin before test day: fees and rules can change.
What the ICC F32 Residential Mechanical (Class C) (2015 IRC) Exam Covers
The official content outline has 6 topics:
| Topic | Questions | Share of the exam |
|---|---|---|
| General Requirements | 22 | 32% |
| Appliances and Equipment | 4 | 6% |
| Duct Systems | 11 | 15% |
| Combustion Air | 16 | 23% |
| Chimneys and Vents | 7 | 10% |
| Fuel Supply Systems | 10 | 14% |
How to Prepare for the ICC F32 Residential Mechanical (Class C) (2015 IRC) Exam
Start with the books. This is an open-book exam, so the references on the bulletin's list are your main study tool. Get the editions the bulletin names.
Learn where things are. Read the table of contents and the index of each book until you know where every major subject lives. On test day, finding an answer fast matters more than memorizing it.
Highlight the sections you use most. Check the bulletin's rules on tabs and markings before you add any.
Spend most of your time on the biggest topics. General Requirements and Combustion Air make up 55% of the exam.
Take timed practice exams. The clock trains you to find answers at the pace the real exam needs: about 2 minutes 34 seconds per question.
Aim to pass more than once. One passing score can be luck. Several in a row means you're ready.
Reference Books for the ICC F32 Residential Mechanical (Class C) (2015 IRC) Exam
The listed reference for this exam is the 2015 International Residential Code.
Where to get them:
On Test Day
- Go through the whole exam first. Answer every question you know and bookmark the ones you don't. Every exam lets you come back to bookmarked questions.
- Then go back to your bookmarks and work them out.
- Don't let one question eat your time. You have 3 hours for 70 questions, which is about 2 minutes 34 seconds per question.
- Before you finish, answer anything you skipped. A blank can't earn a point.
Study Tips
Take this practice exam several times. The goal is to consistently clear your exam's passing score — often around 70–75% — so passing feels routine before you walk into the real test.
Don't be distracted by an answer that is merely factually true—focus on whether it actually answers the question. Always return to the question and verify that your chosen answer directly addresses what's being asked, not just that it's a true statement. Also, when two answers seem equally correct, read all choices carefully and select the one that best answers the question.
Our practice exam is specifically designed to mimic the testing conditions at all exam centers. While untimed PDF study guides might help with studying, they don’t prepare you for the challenge of managing your time during an actual test.
Know your way around each book's index and table of contents. Open-book exams reward speed: you need to find specific items quickly.
Don't let the clock rattle you. It's easy to feel overwhelmed when facing a page full of questions, a racing mind, and a ticking clock. Stay calm and stick to your planned pace. If you've been monitoring your progress consistently, you'll have enough time to finish. Even if the final minutes feel rushed, as long as you have only as many questions remaining as you should at that point, you're exactly where you need to be.
Sample ICC F32 Residential Mechanical (Class C) (2015 IRC) Practice Questions
These questions come from our practice question bank, each with its answer and reference.
Sample 1 — Fuel Supply Systems
Question: A gas-fired appliance that is not listed as flammable-vapor-ignition resistant is being installed in a private garage. The source of ignition must be elevated above the floor not less than:
- A. 4 inches
- B. 12 inches
- C. 18 inches
- D. 6 inches
Correct Answer: C
IRC 2015, Section G2408.2 requires appliances having an ignition source to be elevated so the ignition source is not less than 18 inches above the floor in hazardous locations and in private, public, repair and parking garages, unless the appliance is listed as flammable-vapor-ignition resistant.
Reference: IRC 2015 Section G2408.2
Sample 2 — Chimneys and Vents
Question: A venting system is defined as a continuous open passageway to the outdoor atmosphere for removing flue or vent gases. The passageway begins at which point on the appliance?
- A. The flue collar or draft hood
- B. The relief opening of the vent connector
- C. The combustion chamber outlet
- D. The inlet of the barometric draft regulator
Correct Answer: A
Per IRC 2015 Section G2403 (202), a VENTING SYSTEM is a continuous open passageway from the flue collar or draft hood of an appliance to the outdoor atmosphere, usually composed of a vent or chimney and a vent connector, if used.
Reference: IRC 2015 Section G2403 (202) — definition of VENTING SYSTEM
Sample 3 — Appliances and Equipment
Question: Piping and fittings for refrigerant vapor (suction) lines must be insulated with insulation having a thermal resistivity of not less than:
- A. R-2
- B. R-4
- C. R-3
- D. R-6
Correct Answer: B
IRC 2015, Section M1411.6 requires refrigerant vapor (suction) line piping and fittings to be insulated with insulation having a thermal resistivity of not less than R-4 and an external surface permeance not exceeding 0.05 perm when tested in accordance with ASTM E 96.
Reference: IRC 2015 Section M1411.6
Sample 4 — General Requirements
Question: A listed and labeled transition duct connects a clothes dryer to the rigid exhaust duct system. What is the maximum permitted length of that transition duct?
- A. 6 feet
- B. 12 feet
- C. 10 feet
- D. 8 feet
Correct Answer: D
Per IRC 2015, Section M1502.4.3, transition ducts shall be a single length listed and labeled to UL 2158A, shall not be greater than 8 feet in length, and shall not be concealed within construction.
Reference: IRC 2015 Section M1502.4.3
Why Practice Online Instead of With a PDF
A PDF shows you questions. It doesn't show you the clock. Our practice exams are timed and on a screen, so you practice finding answers under time pressure, not just reading them. Each attempt draws a new set of questions from our bank, and your results break the score down by outline topic so you know what to study next.
Start Practicing
Take the free ICC F32 Residential Mechanical (Class C) (2015 IRC) practice exam to see where you stand, then work through the topics that need attention. For the official rules, read the exam bulletin, and see the licensing board's website.