Gas Appliance Installer Licensing Exam

Gas Appliance Installer Licensing Exam Class A Practice Examination 100 Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of an appliance regulator?
• To ignite the burner
• To maintain a constant manifold pressure
• To monitor the flame
• To adjust combustion air

Rationale: Regulators ensure consistent downstream pressure regardless

of supply pressure fluctuations.

2. A gas appliance must be labeled by:

• The installer
• A recognized testing agency 1 / 3

• The manufacturer only
• The local authority

Rationale: Appliance code requires certification by recognized testing

bodies such as CSA.

• Manifold pressure for a standard natural gas residential furnace is

typically:

• 1.0" w.c.
• 3.5" w.c.
• 7.0" w.c.
• 10.0" w.c.

Rationale: Most NG appliances are designed for 3.5” w.c. burner manifold

pressure.

4. A thermocouple is used to:

• Increase flame size
• Prove pilot flame presence
• Control blower speed
• Regulate manifold pressure

Rationale: Thermocouple signals that the pilot flame is present to prevent

unsafe gas flow.

5. Propane burners operate at a manifold pressure of:

• 2.5" w.c.
• 3.5" w.c. 2 / 3

• 10" w.c.
• 14" w.c.

Rationale: LP requires higher pressure than NG for proper combustion

characteristics.

6. Excessive yellow tipping on a burner flame usually indicates:

• Too much primary air
• Insufficient primary air
• High pressure
• Lack of secondary air

Rationale: Yellow flame indicates incomplete combustion due to low air-

gas mixture.

7. The high-limit switch in a furnace protects against:

• Pilot outage
• Overheating the heat exchanger
• Over-voltage
• Gas over-pressure

Rationale: Limits shut the burner if plenum temperature exceeds safe

operating levels.

8. A Category IV appliance vents:

• Vertically only
• Through a chimney liner
• Via sealed, direct vent with positive static pressure
• / 3