,NYC CUSTODIAN ENGINEER EXAM
COMPLETE PRACTICE TEST BANK — QUESTIONS 1-200
WITH CORRECT ANSWERS AND DETAILED RATIONALES
SECTION 1: BOILER OPERATION & MAINTENANCE
(Questions 1-40)
Question 1
What is the primary responsibility of a NYC Custodian Engineer in a public building?
A) Designing building blueprints
B) Supervising construction crews
C) Maintaining and operating building systems
D) Conducting fire inspections
Answer: C) Maintaining and operating building systems
Rationale: Custodian engineers are responsible for the overall operation, maintenance,
and safety of school facilities and mechanical systems. This includes managing complex
school physical plants, supervising staff, working within budgets, and understanding DOE
procedures.
,Question 2
A Custodian Engineer discovers that a low-pressure boiler is short-cycling repeatedly
during peak heating hours. What is the MOST appropriate first action?
A) Immediately shut down the boiler and call for emergency service
B) Check the boiler's operating control settings and differential
C) Increase the boiler's firing rate
D) Bleed the radiators throughout the building
Answer: B) Check the boiler's operating control settings and differential
Rationale: Short-cycling is often caused by improper control settings, such as a narrow
differential or incorrectly set operating controls. The first step is to verify and adjust the
settings before escalating. Inspecting pressure controls and operating controls is the proper
first troubleshooting step.
Question 3
According to NYC Mechanical Code, what is the maximum allowable pressure for a low-
pressure steam boiler?
A) 5 psi
B) 15 psi
C) 100 psi
D) 150 psi
Answer: B) 15 psi
Rationale: Low-pressure steam boilers are limited to 15 psig. Any boiler operating above
this pressure requires a different class of licensure and stricter operating protocols. This is a
critical safety limit that all custodians must know.
, Question 4
Which safety device prevents a boiler from exceeding its maximum pressure?
A) Thermostat
B) Pressure relief valve
C) Water level gauge
D) Feedwater pump
Answer: B) Pressure relief valve
Rationale: Safety relief valves automatically release excess pressure to prevent boiler
explosions. Safety valves are designed to relieve excess pressure when the boiler exceeds its
maximum operating pressure. They must be tested regularly and replaced if defective.
Question 5
A Custodian Engineer notices a faint odor of natural gas in a school boiler room. What is
the FIRST course of action?
A) Locate the main gas shut-off valve and close it
B) Ventilate the area by opening windows and doors
C) Evacuate the area and call 911 from a remote location
D) Ignite a lighter to test for the leak
Answer: C) Evacuate the area and call 911 from a remote location
Rationale: Any action that could create a spark, including using a phone in the area or
operating electrical switches, poses an ignition risk. Evacuation and calling from a safe
remote location is the mandated first step per FDNY safety protocols. The immediate
priority is to stop the gas flow by closing the main shut-off valve, then ventilate and notify
authorities.
COMPLETE PRACTICE TEST BANK — QUESTIONS 1-200
WITH CORRECT ANSWERS AND DETAILED RATIONALES
SECTION 1: BOILER OPERATION & MAINTENANCE
(Questions 1-40)
Question 1
What is the primary responsibility of a NYC Custodian Engineer in a public building?
A) Designing building blueprints
B) Supervising construction crews
C) Maintaining and operating building systems
D) Conducting fire inspections
Answer: C) Maintaining and operating building systems
Rationale: Custodian engineers are responsible for the overall operation, maintenance,
and safety of school facilities and mechanical systems. This includes managing complex
school physical plants, supervising staff, working within budgets, and understanding DOE
procedures.
,Question 2
A Custodian Engineer discovers that a low-pressure boiler is short-cycling repeatedly
during peak heating hours. What is the MOST appropriate first action?
A) Immediately shut down the boiler and call for emergency service
B) Check the boiler's operating control settings and differential
C) Increase the boiler's firing rate
D) Bleed the radiators throughout the building
Answer: B) Check the boiler's operating control settings and differential
Rationale: Short-cycling is often caused by improper control settings, such as a narrow
differential or incorrectly set operating controls. The first step is to verify and adjust the
settings before escalating. Inspecting pressure controls and operating controls is the proper
first troubleshooting step.
Question 3
According to NYC Mechanical Code, what is the maximum allowable pressure for a low-
pressure steam boiler?
A) 5 psi
B) 15 psi
C) 100 psi
D) 150 psi
Answer: B) 15 psi
Rationale: Low-pressure steam boilers are limited to 15 psig. Any boiler operating above
this pressure requires a different class of licensure and stricter operating protocols. This is a
critical safety limit that all custodians must know.
, Question 4
Which safety device prevents a boiler from exceeding its maximum pressure?
A) Thermostat
B) Pressure relief valve
C) Water level gauge
D) Feedwater pump
Answer: B) Pressure relief valve
Rationale: Safety relief valves automatically release excess pressure to prevent boiler
explosions. Safety valves are designed to relieve excess pressure when the boiler exceeds its
maximum operating pressure. They must be tested regularly and replaced if defective.
Question 5
A Custodian Engineer notices a faint odor of natural gas in a school boiler room. What is
the FIRST course of action?
A) Locate the main gas shut-off valve and close it
B) Ventilate the area by opening windows and doors
C) Evacuate the area and call 911 from a remote location
D) Ignite a lighter to test for the leak
Answer: C) Evacuate the area and call 911 from a remote location
Rationale: Any action that could create a spark, including using a phone in the area or
operating electrical switches, poses an ignition risk. Evacuation and calling from a safe
remote location is the mandated first step per FDNY safety protocols. The immediate
priority is to stop the gas flow by closing the main shut-off valve, then ventilate and notify
authorities.
