Exam Cheat Sheet · Quick Reference

Idaho - HVAC SPECIALTY JOURNEYMAN EXAM

Idaho  ·  PSI Services Contractor

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
50
Passing score
70
Exam time
120 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

Idaho State Portion 50 questions

2018 International Fuel Gas Code (IFGC) - Capítulo 1 6 Q · 12%
2018 International Fuel Gas Code (IFGC) - Capítulo 2 6 Q · 12%
2018 International Fuel Gas Code (IFGC) - Capítulo 3 7 Q · 14%
2018 International Fuel Gas Code (IFGC) - Capítulo 4 9 Q · 18%
2018 International Fuel Gas Code (IFGC) - Capítulo 5 8 Q · 16%
2018 International Fuel Gas Code (IFGC) - Capítulo 6 7 Q · 14%
2018 International Fuel Gas Code (IFGC) - Capítulo 7 7 Q · 14%

Key Distinctions

Natural Gas Piping Max PressurevsLP-Gas Piping Max Pressure

IFGC covers natural gas piping at 125 psig or less, but LP-gas piping only at 20 psig or less (except per Section 402.7).

2018 International Fuel Gas Code (IFGC), Section 101.2.2
Category I AppliancevsCategory IV Appliance

Category I operates with nonpositive vent static pressure and avoids excessive condensate; Category IV operates with positive vent static pressure and produces excessive condensate.

2018 International Fuel Gas Code (IFGC), Chapter 2, Section 202
Low-Heat AppliancevsMedium-Heat Appliance

Low-heat appliances have flue entrance combustion temperatures of 1,000°F or less; medium-heat appliances exceed 1,000°F but do not exceed 2,000°F.

2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
Hot Water Heating BoilervsSteam Heating Boiler

A hot water heating boiler circulates hot water at no more than 160 psig and 250°F; a steam heating boiler generates steam at no more than 15 psig.

2018 International Fuel Gas Code (IFGC), Chapter 2, Section 202
Direct-Vent AppliancevsStandard Vented Appliance

A direct-vent appliance draws all combustion air from outdoors and discharges all flue gases outdoors; a standard vented appliance (e.g., Category I with Type B vent) uses indoor air and a conventional vent system.

2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
General RequirementvsSpecific Requirement

Where there is a conflict between a general requirement and a specific requirement in the IFGC, the specific requirement governs.

2018 International Fuel Gas Code (IFGC), Section 102.1
Normal Permit WorkvsEmergency Permit Work

Normal work requires a permit before commencing; emergency appliance/equipment replacement allows work to start immediately but the permit application must be submitted within the next working business day.

2018 International Fuel Gas Code (IFGC), Section 106.1 Exception
Private Garage Appliance InstallationvsPublic Garage Appliance Installation

Private garages require a minimum clearance of 6 feet above the floor; public garages require at least 8 feet above the floor, or 1 foot higher than the tallest vehicle door opening if vehicles pass under the appliance.

2018 International Fuel Gas Code (IFGC), Section 305.5
Standard Method (Indoor Combustion Air)vsTwo-Permanent-Openings Method (Outdoor Combustion Air)

The Standard Method requires 50 cubic feet of indoor volume per 1,000 Btu/h of input; the Two-Permanent-Openings Method requires each opening to have at least 1 square inch of free area per 4,000 Btu/h of total input.

2018 International Fuel Gas Code (IFGC), Section 304.5.1
BrazingvsSoldering

Brazing uses a nonferrous filler metal with a melting point above 1,000°F (but below the base metal); soldering uses filler metals with a melting point below 1,000°F.

2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
Rough-In InspectionvsUnderground Inspection

Underground inspection is made after trenches are excavated and piping is installed before backfill; rough-in inspection is made after framing and fireblocking are in place but before wall/ceiling membranes are installed.

2018 International Fuel Gas Code (IFGC), Section 107.2
Existing Lawful InstallationvsNew Installation

Existing installations lawfully in place at code adoption may continue without being required to comply with all current IFGC requirements; new installations must fully comply with the current code.

2018 International Fuel Gas Code (IFGC), Section 102.2

Key Terms

Maximum Permit Commencement Period 2018 International Fuel Gas Code (IFGC), Section 106.5.3
Per 2018 IFGC Section 106.5.3, a permit becomes null and void if authorized work is not commenced within 180 days of issuance, or is suspended/abandoned for 180 days after commencement.
Penalty for Commencing Work Without a Permit 2018 International Fuel Gas Code (IFGC), Section 106.6.1
Per 2018 IFGC Section 106.6.1, any person who starts work before obtaining the necessary permit is subject to an additional fee equal to 100 percent of the usual permit fee on top of required permit fees.
Emergency Permit Submission Rule 2018 International Fuel Gas Code (IFGC), Section 106.1 Exception
Per 2018 IFGC Section 106.1 Exception, when appliance/equipment replacement or repair is required in an emergency, the permit application must be submitted within the next working business day of the Department of Inspection.
Alternative Material Denial Response 2018 International Fuel Gas Code (IFGC), Section 105.2
Per 2018 IFGC Section 105.2, if the code official does not approve an alternative material, design, or method, the official must respond in writing stating the reasons for denial.
Change of Occupancy Certification 2018 International Fuel Gas Code (IFGC), Section 102.5
Per 2018 IFGC Section 102.5, the code official must certify that a structure meets the intent of the code provisions for a proposed new occupancy and that the change does not create hazards to public health, safety, or welfare.
Existing Installation Continuance 2018 International Fuel Gas Code (IFGC), Section 102.2
Per 2018 IFGC Section 102.2, the code does not require removal, alteration, or abandonment of existing installations that were lawfully in place at the time of code adoption.
Specific vs. General Requirement Conflict Rule 2018 International Fuel Gas Code (IFGC), Section 102.1
Per 2018 IFGC Section 102.1, where a general requirement and a specific requirement conflict, the specific requirement governs.
Undefined Terms Rule 2018 International Fuel Gas Code (IFGC), Chapter 2, Section 201.3
Per 2018 IFGC Section 201.3, terms not defined in the IFGC but defined in the International Building Code, Fire Code, Mechanical Code, or Plumbing Code shall have the meanings ascribed in those codes.
Oxygen Depletion Safety Shutoff System (ODS) 2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
A system that automatically shuts off gas supply to main and pilot burners if oxygen in the surrounding atmosphere drops below a predetermined level.
Point of Delivery (Natural Gas) 2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
The outlet of the service meter assembly, or the outlet of the service regulator or service shutoff valve where a meter is not provided.
Bonding Jumper 2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
A conductor installed to electrically connect metallic gas piping to the grounding electrode system.
BTU (British Thermal Unit) 2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
The quantity of heat required to raise the temperature of 1 pound of water 1°F.
Type B Vent 2018 International Fuel Gas Code (IFGC) (Idaho), Chapter 2, Section 202
A vent listed and labeled for use with appliances with draft hoods and other Category I appliances listed for use with Type B vents.
Condensate Drain Pipe Minimum Diameter 2018 International Fuel Gas Code (IFGC), Section 307.3
Per 2018 IFGC Section 307.3, condensate waste and drain line shall be not less than 3/4-inch internal diameter and shall not decrease in size toward the point of disposal.
Condensate Piping Minimum Slope 2018 International Fuel Gas Code (IFGC), Section 307.2
Per 2018 IFGC Section 307.2, condensate piping must slope at least 1/8 unit vertical per 12 units horizontal (1-percent slope) in the direction of discharge.
Attic Passageway Maximum Length 2018 International Fuel Gas Code (IFGC), Section 306.3
Per 2018 IFGC Section 306.3, an attic passageway to an appliance shall not exceed 20 feet in length unless the passageway is at least 6 feet high for its entire length, in which case 50 feet is permitted.

Formulas to Know

Standard Method – Minimum Indoor Air Volume for CombustionMinimum Volume (ft³) = (Appliance Input Rating in Btu/h ÷ 1,000) × 50
Two-Permanent-Openings Method – Minimum Free Area per OpeningMin Free Area (in²) = Total Appliance Input Rating (Btu/h) ÷ 4,000
Condensate Pipe SlopeMin Slope = 1/8 in vertical per 12 in horizontal (1% slope)
Penalty Fee for Work Without PermitTotal Fee = Required Permit Fee + (100% × Usual Permit Fee)
Public Garage Appliance Height (vehicles passing under)Min Height (ft) = Tallest Vehicle Door Opening (ft) + 1 ft [minimum 8 ft absolute]
Private Garage Appliance Minimum HeightMin Height = 6 ft above floor