NYC CUSTODIAN ENGINEER EXAM
2026/2027 COMPREHENSIVE
PREPARATION QUESTIONS AND
ANSWERS
1. When a high-pressure steam boiler is operating, what is the most critical function of the
low-water fuel cut-off?
A. To shut down the burner to prevent damage from overheating
B. To increase the burner firing rate if pressure drops
C. To open the blowdown valve automatically
D. To monitor the chemical concentration in the boiler drum
Answer: A
Conceptual Explanation: The low-water fuel cut-off is the primary safety device designed
to prevent a dry-fire condition, which could lead to a catastrophic boiler explosion or
melting of the tubes/shell.
2. Under NYC Department of Buildings (DOB) regulations, how often must a high-pressure
boiler be internally inspected?
A. Every five years
,B. Every six months
C. Every two years
D. Annually
Answer: D
Conceptual Explanation: NYC DOB requires annual internal and external inspections for
high-pressure boilers to ensure compliance with safety standards.
3. Which of the following describes the ‘compression’ stage in a standard refrigeration cycle?
A. Low-pressure liquid is turned into a high-pressure gas
B. Low-pressure vapor is compressed into a high-pressure vapor
C. High-pressure vapor is cooled into a liquid
D. High-pressure liquid is expanded into a low-pressure liquid
Answer: B
Conceptual Explanation: The compressor takes low-pressure suction gas and raises its
pressure and temperature before sending it to the condenser.
4. What is the required FDNY certificate of fitness for a person supervising a standpipe system
in a NYC school building?
A. G-60
B. F-01
, C. S-13
D. S-95
Answer: C
Conceptual Explanation: The S-13 (Citywide Standpipe System) is required for the
inspection, testing, and maintenance of standpipe systems in New York City.
5. If a centrifugal pump is ‘cavitating’, which of the following is the most likely cause?
A. The discharge valve is fully open
B. The pump is running too slow
C. The motor is wired in reverse rotation
D. Absolute pressure at the suction inlet is below the vapor pressure of the liquid
Answer: D
Conceptual Explanation: Cavitation occurs when the Net Positive Suction Head Available
(NPSHA) is lower than required, causing vapor bubbles to form and collapse against the
impeller.
6. Local Law 97 of 2019 primarily addresses which aspect of NYC building management?
A. Annual boiler efficiency tuning
B. Standardized fire alarm testing protocols
C. Mandatory lead paint removal in schools
2026/2027 COMPREHENSIVE
PREPARATION QUESTIONS AND
ANSWERS
1. When a high-pressure steam boiler is operating, what is the most critical function of the
low-water fuel cut-off?
A. To shut down the burner to prevent damage from overheating
B. To increase the burner firing rate if pressure drops
C. To open the blowdown valve automatically
D. To monitor the chemical concentration in the boiler drum
Answer: A
Conceptual Explanation: The low-water fuel cut-off is the primary safety device designed
to prevent a dry-fire condition, which could lead to a catastrophic boiler explosion or
melting of the tubes/shell.
2. Under NYC Department of Buildings (DOB) regulations, how often must a high-pressure
boiler be internally inspected?
A. Every five years
,B. Every six months
C. Every two years
D. Annually
Answer: D
Conceptual Explanation: NYC DOB requires annual internal and external inspections for
high-pressure boilers to ensure compliance with safety standards.
3. Which of the following describes the ‘compression’ stage in a standard refrigeration cycle?
A. Low-pressure liquid is turned into a high-pressure gas
B. Low-pressure vapor is compressed into a high-pressure vapor
C. High-pressure vapor is cooled into a liquid
D. High-pressure liquid is expanded into a low-pressure liquid
Answer: B
Conceptual Explanation: The compressor takes low-pressure suction gas and raises its
pressure and temperature before sending it to the condenser.
4. What is the required FDNY certificate of fitness for a person supervising a standpipe system
in a NYC school building?
A. G-60
B. F-01
, C. S-13
D. S-95
Answer: C
Conceptual Explanation: The S-13 (Citywide Standpipe System) is required for the
inspection, testing, and maintenance of standpipe systems in New York City.
5. If a centrifugal pump is ‘cavitating’, which of the following is the most likely cause?
A. The discharge valve is fully open
B. The pump is running too slow
C. The motor is wired in reverse rotation
D. Absolute pressure at the suction inlet is below the vapor pressure of the liquid
Answer: D
Conceptual Explanation: Cavitation occurs when the Net Positive Suction Head Available
(NPSHA) is lower than required, causing vapor bubbles to form and collapse against the
impeller.
6. Local Law 97 of 2019 primarily addresses which aspect of NYC building management?
A. Annual boiler efficiency tuning
B. Standardized fire alarm testing protocols
C. Mandatory lead paint removal in schools
