[NYC CUSTODIAN ENGINEER EXAM] – QUESTIONS AND
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS
RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE |
EXAM PREP | STUDY GUIDE | PRACTICE TEST
1. 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. Replace the circulating pump immediately
B. Increase the thermostat setting throughout the building
C. Inspect the pressure control and operating controls
D. Shut down the boiler for the remainder of the day
════════════════════
Correct Answer: C. Inspect the pressure control and operating controls
Rationale:
Short-cycling is commonly caused by faulty pressure controls, limit settings, or operating
controls. Inspecting and verifying control operation is the proper first troubleshooting step
before replacing components or shutting down equipment unnecessarily. Increasing
thermostat settings could worsen the issue, while immediate shutdown may not be warranted
unless a dangerous condition exists.
════════════════════
2. During a routine inspection, a Custodian Engineer notices corrosion around a condensate
return line. What is the BEST immediate response?
A. Paint over the affected section
B. Isolate and inspect the line for leaks or structural weakness
C. Increase system pressure to test durability
D. Ignore the condition until annual maintenance
════════════════════
Correct Answer: B. Isolate and inspect the line for leaks or structural weakness
Rationale:
Corrosion on condensate return piping may indicate active leakage or deterioration that could
lead to failure. Isolating and inspecting the affected section prevents escalation and supports
,safe operation. Painting over corrosion is cosmetic only, and increasing pressure could worsen
damage.
════════════════════
3. A school building experiences uneven heating between floors. Which condition is MOST
likely responsible?
A. Excessive domestic water temperature
B. Defective sprinkler heads
C. Improper balancing of heating zones
D. Oversized electrical transformers
════════════════════
Correct Answer: C. Improper balancing of heating zones
Rationale:
Uneven heating commonly results from improper balancing of valves, zones, or distribution
systems. Heating systems require proper flow balancing to ensure consistent heat delivery
throughout the building. Domestic water temperature and transformers are unrelated to
heating distribution performance.
════════════════════
4. Which document should always be reviewed BEFORE authorizing contractor work in a NYC
public building?
A. Elevator inspection sticker
B. Employee attendance sheet
C. Daily cafeteria inventory
D. Scope of work and safety compliance documentation
════════════════════
Correct Answer: D. Scope of work and safety compliance documentation
Rationale:
Reviewing the scope of work and applicable safety documentation ensures contractors
understand operational, regulatory, and safety expectations before beginning work. This
protects building occupants, equipment, and compliance obligations.
════════════════════
,5. A Custodian Engineer detects an unusual vibration in a centrifugal pump. What is the MOST
likely cause?
A. Misalignment or bearing wear
B. Excessive thermostat sensitivity
C. Low lighting levels in the mechanical room
D. Properly balanced impeller rotation
════════════════════
Correct Answer: A. Misalignment or bearing wear
Rationale:
Pump vibration is frequently caused by shaft misalignment, worn bearings, cavitation, or
impeller imbalance. These mechanical issues can lead to premature equipment failure if not
corrected promptly. Properly balanced equipment should operate smoothly with minimal
vibration.
════════════════════
6. When responding to a fire alarm activation, what should be the Custodian Engineer’s
PRIORITY?
A. Resume HVAC operations immediately
B. Silence all alarms to avoid panic
C. Ensure life safety procedures are followed and verify alarm conditions
D. Restart elevators manually
════════════════════
Correct Answer: C. Ensure life safety procedures are followed and verify alarm conditions
Rationale:
Life safety is always the top priority during fire alarm incidents. The Custodian Engineer must
verify alarm conditions, support evacuation procedures, and coordinate with emergency
responders as necessary. Silencing alarms or restarting systems prematurely may endanger
occupants.
════════════════════
7. A boiler feed pump continues operating after the boiler reaches normal water level. Which
component should be inspected FIRST?
, A. Fuel oil filter
B. Water level controller
C. Smoke detector
D. Expansion tank
════════════════════
Correct Answer: B. Water level controller
Rationale:
A malfunctioning water level controller may fail to signal the feed pump to stop, leading to
overfilling or unsafe operation. The controller is the most direct component related to pump
cycling behavior.
════════════════════
8. Which maintenance practice BEST improves energy efficiency in HVAC systems?
A. Disabling automatic controls
B. Operating all equipment continuously
C. Ignoring air filter replacement schedules
D. Performing regular preventive maintenance and calibration
════════════════════
Correct Answer: D. Performing regular preventive maintenance and calibration
Rationale:
Preventive maintenance, including filter replacement, calibration, lubrication, and system
inspection, improves HVAC efficiency and reduces energy waste. Poor maintenance increases
operating costs and decreases equipment lifespan.
════════════════════
9. A Custodian Engineer must enter a confined space to inspect piping. What is REQUIRED
before entry?
A. Increase ventilation after entry
B. Remove all warning signs
C. Conduct atmospheric testing and follow confined space procedures
D. Enter quickly to minimize exposure
════════════════════
Correct Answer: C. Conduct atmospheric testing and follow confined space procedures
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS
RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE |
EXAM PREP | STUDY GUIDE | PRACTICE TEST
1. 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. Replace the circulating pump immediately
B. Increase the thermostat setting throughout the building
C. Inspect the pressure control and operating controls
D. Shut down the boiler for the remainder of the day
════════════════════
Correct Answer: C. Inspect the pressure control and operating controls
Rationale:
Short-cycling is commonly caused by faulty pressure controls, limit settings, or operating
controls. Inspecting and verifying control operation is the proper first troubleshooting step
before replacing components or shutting down equipment unnecessarily. Increasing
thermostat settings could worsen the issue, while immediate shutdown may not be warranted
unless a dangerous condition exists.
════════════════════
2. During a routine inspection, a Custodian Engineer notices corrosion around a condensate
return line. What is the BEST immediate response?
A. Paint over the affected section
B. Isolate and inspect the line for leaks or structural weakness
C. Increase system pressure to test durability
D. Ignore the condition until annual maintenance
════════════════════
Correct Answer: B. Isolate and inspect the line for leaks or structural weakness
Rationale:
Corrosion on condensate return piping may indicate active leakage or deterioration that could
lead to failure. Isolating and inspecting the affected section prevents escalation and supports
,safe operation. Painting over corrosion is cosmetic only, and increasing pressure could worsen
damage.
════════════════════
3. A school building experiences uneven heating between floors. Which condition is MOST
likely responsible?
A. Excessive domestic water temperature
B. Defective sprinkler heads
C. Improper balancing of heating zones
D. Oversized electrical transformers
════════════════════
Correct Answer: C. Improper balancing of heating zones
Rationale:
Uneven heating commonly results from improper balancing of valves, zones, or distribution
systems. Heating systems require proper flow balancing to ensure consistent heat delivery
throughout the building. Domestic water temperature and transformers are unrelated to
heating distribution performance.
════════════════════
4. Which document should always be reviewed BEFORE authorizing contractor work in a NYC
public building?
A. Elevator inspection sticker
B. Employee attendance sheet
C. Daily cafeteria inventory
D. Scope of work and safety compliance documentation
════════════════════
Correct Answer: D. Scope of work and safety compliance documentation
Rationale:
Reviewing the scope of work and applicable safety documentation ensures contractors
understand operational, regulatory, and safety expectations before beginning work. This
protects building occupants, equipment, and compliance obligations.
════════════════════
,5. A Custodian Engineer detects an unusual vibration in a centrifugal pump. What is the MOST
likely cause?
A. Misalignment or bearing wear
B. Excessive thermostat sensitivity
C. Low lighting levels in the mechanical room
D. Properly balanced impeller rotation
════════════════════
Correct Answer: A. Misalignment or bearing wear
Rationale:
Pump vibration is frequently caused by shaft misalignment, worn bearings, cavitation, or
impeller imbalance. These mechanical issues can lead to premature equipment failure if not
corrected promptly. Properly balanced equipment should operate smoothly with minimal
vibration.
════════════════════
6. When responding to a fire alarm activation, what should be the Custodian Engineer’s
PRIORITY?
A. Resume HVAC operations immediately
B. Silence all alarms to avoid panic
C. Ensure life safety procedures are followed and verify alarm conditions
D. Restart elevators manually
════════════════════
Correct Answer: C. Ensure life safety procedures are followed and verify alarm conditions
Rationale:
Life safety is always the top priority during fire alarm incidents. The Custodian Engineer must
verify alarm conditions, support evacuation procedures, and coordinate with emergency
responders as necessary. Silencing alarms or restarting systems prematurely may endanger
occupants.
════════════════════
7. A boiler feed pump continues operating after the boiler reaches normal water level. Which
component should be inspected FIRST?
, A. Fuel oil filter
B. Water level controller
C. Smoke detector
D. Expansion tank
════════════════════
Correct Answer: B. Water level controller
Rationale:
A malfunctioning water level controller may fail to signal the feed pump to stop, leading to
overfilling or unsafe operation. The controller is the most direct component related to pump
cycling behavior.
════════════════════
8. Which maintenance practice BEST improves energy efficiency in HVAC systems?
A. Disabling automatic controls
B. Operating all equipment continuously
C. Ignoring air filter replacement schedules
D. Performing regular preventive maintenance and calibration
════════════════════
Correct Answer: D. Performing regular preventive maintenance and calibration
Rationale:
Preventive maintenance, including filter replacement, calibration, lubrication, and system
inspection, improves HVAC efficiency and reduces energy waste. Poor maintenance increases
operating costs and decreases equipment lifespan.
════════════════════
9. A Custodian Engineer must enter a confined space to inspect piping. What is REQUIRED
before entry?
A. Increase ventilation after entry
B. Remove all warning signs
C. Conduct atmospheric testing and follow confined space procedures
D. Enter quickly to minimize exposure
════════════════════
Correct Answer: C. Conduct atmospheric testing and follow confined space procedures
