LA County Mechanical Inspector
Promotional Exam Level II Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026-2027 Q&A |
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1. Which of the following best describes the primary purpose of a
mechanical inspection?
A. To install mechanical systems
B. To ensure systems comply with codes and operate safely
C. To design HVAC systems
D. To supervise construction crews
B
Mechanical inspections verify compliance with building and safety
codes to protect public health and safety.
2. A mechanical inspector encounters a gas furnace vented with PVC
in a residential building. What should they check first?
A. Manufacturer’s specifications
B. Local building codes and venting requirements
C. Electrical wiring
D. Duct insulation
B
, PVC venting may be allowed only under certain codes; inspectors
must ensure code compliance before evaluating installation.
3. When inspecting a hydronic heating system, the inspector notices
water dripping from a pressure relief valve. This indicates:
A. Normal operation
B. Excessive system pressure
C. Low water temperature
D. Clogged filter
B
Pressure relief valves release water to prevent overpressure;
dripping usually indicates excessive pressure in the system.
4. A mechanical inspector is reviewing HVAC plans. Which document
provides the most detailed installation instructions?
A. Mechanical code book
B. Manufacturer’s installation manual
C. Building permit
D. Architectural drawings
B
Manufacturer manuals give specific installation instructions and
are referenced during inspections.
5. What is the minimum clearance typically required around a
mechanical furnace for servicing?
A. 6 inches
B. 18 inches
C. 36 inches
D. 48 inches
C
, Most codes require a 36-inch minimum clearance in front of a
furnace for safe access and maintenance.
6. Which of the following is a sign of a blocked HVAC air filter?
A. Increased airflow
B. Uneven temperature distribution
C. No change in system performance
D. Reduced energy bills
B
A clogged filter restricts airflow, reducing system efficiency and
causing uneven heating or cooling.
7. What is the primary function of a backflow preventer in a
mechanical system?
A. Reduce water pressure
B. Prevent reverse flow of water or contaminants
C. Increase water temperature
D. Regulate water chemical levels
B
Backflow preventers protect potable water by stopping
contaminated water from flowing back into the supply.
8. Which type of duct material is typically required for exhaust ducts
in commercial kitchens?
A. PVC
B. Galvanized steel
C. Copper
D. PEX
B
, Galvanized steel is required for grease-laden exhausts due to fire
resistance and durability.
9. A mechanical inspector finds a gas line with inadequate support
spacing. Which is the likely concern?
A. Pressure drop
B. Pipe sagging or movement
C. Gas leakage from corrosion
D. Electrical interference
B
Proper support prevents sagging or stress at joints, reducing the
risk of leaks.
10. What should an inspector do if they encounter a non-
permitted mechanical installation?
A. Approve it if it looks safe
B. Document the violation and notify the building department
C. Make corrections themselves
D. Ignore minor issues
B
Inspectors must enforce code compliance by reporting non-
permitted installations.
11. When inspecting a rooftop HVAC unit, the inspector notices
the unit is tilted. What is the most likely concern?
A. Reduced airflow
B. Improper drainage leading to water accumulation
C. Increased heating capacity
D. Over-insulation of ducts
B
Promotional Exam Level II Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026-2027 Q&A |
Instant Download Pdf
1. Which of the following best describes the primary purpose of a
mechanical inspection?
A. To install mechanical systems
B. To ensure systems comply with codes and operate safely
C. To design HVAC systems
D. To supervise construction crews
B
Mechanical inspections verify compliance with building and safety
codes to protect public health and safety.
2. A mechanical inspector encounters a gas furnace vented with PVC
in a residential building. What should they check first?
A. Manufacturer’s specifications
B. Local building codes and venting requirements
C. Electrical wiring
D. Duct insulation
B
, PVC venting may be allowed only under certain codes; inspectors
must ensure code compliance before evaluating installation.
3. When inspecting a hydronic heating system, the inspector notices
water dripping from a pressure relief valve. This indicates:
A. Normal operation
B. Excessive system pressure
C. Low water temperature
D. Clogged filter
B
Pressure relief valves release water to prevent overpressure;
dripping usually indicates excessive pressure in the system.
4. A mechanical inspector is reviewing HVAC plans. Which document
provides the most detailed installation instructions?
A. Mechanical code book
B. Manufacturer’s installation manual
C. Building permit
D. Architectural drawings
B
Manufacturer manuals give specific installation instructions and
are referenced during inspections.
5. What is the minimum clearance typically required around a
mechanical furnace for servicing?
A. 6 inches
B. 18 inches
C. 36 inches
D. 48 inches
C
, Most codes require a 36-inch minimum clearance in front of a
furnace for safe access and maintenance.
6. Which of the following is a sign of a blocked HVAC air filter?
A. Increased airflow
B. Uneven temperature distribution
C. No change in system performance
D. Reduced energy bills
B
A clogged filter restricts airflow, reducing system efficiency and
causing uneven heating or cooling.
7. What is the primary function of a backflow preventer in a
mechanical system?
A. Reduce water pressure
B. Prevent reverse flow of water or contaminants
C. Increase water temperature
D. Regulate water chemical levels
B
Backflow preventers protect potable water by stopping
contaminated water from flowing back into the supply.
8. Which type of duct material is typically required for exhaust ducts
in commercial kitchens?
A. PVC
B. Galvanized steel
C. Copper
D. PEX
B
, Galvanized steel is required for grease-laden exhausts due to fire
resistance and durability.
9. A mechanical inspector finds a gas line with inadequate support
spacing. Which is the likely concern?
A. Pressure drop
B. Pipe sagging or movement
C. Gas leakage from corrosion
D. Electrical interference
B
Proper support prevents sagging or stress at joints, reducing the
risk of leaks.
10. What should an inspector do if they encounter a non-
permitted mechanical installation?
A. Approve it if it looks safe
B. Document the violation and notify the building department
C. Make corrections themselves
D. Ignore minor issues
B
Inspectors must enforce code compliance by reporting non-
permitted installations.
11. When inspecting a rooftop HVAC unit, the inspector notices
the unit is tilted. What is the most likely concern?
A. Reduced airflow
B. Improper drainage leading to water accumulation
C. Increased heating capacity
D. Over-insulation of ducts
B
