NYC Custodian Engineer Prep Class Questions 2026 | Most
Tested Questions & Verified Answers | Graded A+
1. If a heating system is producing carbon monoxide, what does this indicate
about the combustion process?
It indicates that the fuel is of poor quality.
It indicates that incomplete combustion is occurring due to
insufficient oxygen.
It indicates that the heating system is functioning optimally.
It indicates that complete combustion is occurring efficiently.
2. Describe how air in the fuel line can affect fuel oil pressure in a heating
system.
Air in the fuel line has no effect on fuel oil pressure.
Air in the fuel line can create bubbles that disrupt the flow of fuel,
leading to pressure fluctuations.
Air in the fuel line helps to stabilize fuel flow.
Air in the fuel line increases the overall pressure of the system.
3. What is a key feature of steam unit heaters when they are in the process of
heating up?
They operate at a constant temperature.
They require immediate maintenance.
They provide a gradual increase in temperature.
They emit cold air initially.
,4. If a facility manager decides to switch from semi-automatic to fully automatic
control for a horizontal rotary oil burner, what changes might occur in the
ignition and starting process?
The ignition and starting process would become fully automated,
reducing the need for manual intervention.
The ignition process would require more manual checks and
oversight.
The ignition would be completely eliminated from the process.
The starting process would remain unchanged but require additional
safety protocols.
5. A duplex reciprocating feedwater pump operates on the principle that
______________________________.
the steam piston must be 2 to 2.5 times larger in area than the water
piston
the water piston must be 2 to 2.5 times larger in area than the steam
piston
the piston speed squared will equal gallons per minute
the steam side must be 2 to 2.5 times larger in area than the water side
6. If a school decides to upgrade its bell system to a modern multiple circuit
program instrument, what potential benefit could this upgrade provide?
Increased energy consumption during operation.
Increased reliability and reduced manual intervention.
Less flexibility in scheduling bell times.
Higher costs due to complex installation.
,7. Describe how disinfectants contribute to hygiene in toilet rooms.
Disinfectants are used to polish surfaces.
Disinfectants are primarily used for their pleasant scent.
Disinfectants only remove visible dirt and grime.
Disinfectants help maintain hygiene by killing harmful bacteria and
viruses present in toilet rooms.
8. If a facility manager is tasked with improving the efficiency of cleaning
operations, how might they incorporate sodium silicate into their strategy?
By avoiding the use of sodium silicate due to safety concerns.
By using sodium silicate solely for water treatment.
By replacing all cleaning agents with sodium silicate.
By using sodium silicate to enhance the effectiveness of cleaning
agents.
9. Describe the role of a fusible plug in maintaining boiler safety.
The fusible plug monitors water quality.
The fusible plug regulates the pressure within the boiler.
The fusible plug ensures proper fuel combustion.
The fusible plug melts at high temperatures, allowing water to
escape and preventing boiler damage.
10. What type of cleaning agent is recommended for greasy chrome plated
fittings?
Bleach solution
Abrasive cleaner
, Acidic cleaner
A mild detergent solution
11. What is the primary purpose of disinfectants in cleaning solutions for toilet
rooms?
To remove stains from surfaces.
To provide a protective coating on surfaces.
To enhance the fragrance of the cleaning solution.
To kill or inactivate harmful microorganisms.
12. In a scenario where an oil supply pump experiences a discharge line
blockage, what would be the immediate action to take to ensure the pump's
safety?
Engage the bypass valve to redirect the oil flow.
Increase the pump's speed to force the oil through.
Shut down the entire system immediately.
Check the oil level in the tank.
13. If a science room is found to have rubber hose attachments that extend
below the sink rim, what immediate action should be taken to ensure safety?
Increase the water pressure to flush the system.
Remove the hose attachments to prevent backflow contamination.
Install a filtration system to clean the water.
Ignore the issue if no contamination is visible.
Tested Questions & Verified Answers | Graded A+
1. If a heating system is producing carbon monoxide, what does this indicate
about the combustion process?
It indicates that the fuel is of poor quality.
It indicates that incomplete combustion is occurring due to
insufficient oxygen.
It indicates that the heating system is functioning optimally.
It indicates that complete combustion is occurring efficiently.
2. Describe how air in the fuel line can affect fuel oil pressure in a heating
system.
Air in the fuel line has no effect on fuel oil pressure.
Air in the fuel line can create bubbles that disrupt the flow of fuel,
leading to pressure fluctuations.
Air in the fuel line helps to stabilize fuel flow.
Air in the fuel line increases the overall pressure of the system.
3. What is a key feature of steam unit heaters when they are in the process of
heating up?
They operate at a constant temperature.
They require immediate maintenance.
They provide a gradual increase in temperature.
They emit cold air initially.
,4. If a facility manager decides to switch from semi-automatic to fully automatic
control for a horizontal rotary oil burner, what changes might occur in the
ignition and starting process?
The ignition and starting process would become fully automated,
reducing the need for manual intervention.
The ignition process would require more manual checks and
oversight.
The ignition would be completely eliminated from the process.
The starting process would remain unchanged but require additional
safety protocols.
5. A duplex reciprocating feedwater pump operates on the principle that
______________________________.
the steam piston must be 2 to 2.5 times larger in area than the water
piston
the water piston must be 2 to 2.5 times larger in area than the steam
piston
the piston speed squared will equal gallons per minute
the steam side must be 2 to 2.5 times larger in area than the water side
6. If a school decides to upgrade its bell system to a modern multiple circuit
program instrument, what potential benefit could this upgrade provide?
Increased energy consumption during operation.
Increased reliability and reduced manual intervention.
Less flexibility in scheduling bell times.
Higher costs due to complex installation.
,7. Describe how disinfectants contribute to hygiene in toilet rooms.
Disinfectants are used to polish surfaces.
Disinfectants are primarily used for their pleasant scent.
Disinfectants only remove visible dirt and grime.
Disinfectants help maintain hygiene by killing harmful bacteria and
viruses present in toilet rooms.
8. If a facility manager is tasked with improving the efficiency of cleaning
operations, how might they incorporate sodium silicate into their strategy?
By avoiding the use of sodium silicate due to safety concerns.
By using sodium silicate solely for water treatment.
By replacing all cleaning agents with sodium silicate.
By using sodium silicate to enhance the effectiveness of cleaning
agents.
9. Describe the role of a fusible plug in maintaining boiler safety.
The fusible plug monitors water quality.
The fusible plug regulates the pressure within the boiler.
The fusible plug ensures proper fuel combustion.
The fusible plug melts at high temperatures, allowing water to
escape and preventing boiler damage.
10. What type of cleaning agent is recommended for greasy chrome plated
fittings?
Bleach solution
Abrasive cleaner
, Acidic cleaner
A mild detergent solution
11. What is the primary purpose of disinfectants in cleaning solutions for toilet
rooms?
To remove stains from surfaces.
To provide a protective coating on surfaces.
To enhance the fragrance of the cleaning solution.
To kill or inactivate harmful microorganisms.
12. In a scenario where an oil supply pump experiences a discharge line
blockage, what would be the immediate action to take to ensure the pump's
safety?
Engage the bypass valve to redirect the oil flow.
Increase the pump's speed to force the oil through.
Shut down the entire system immediately.
Check the oil level in the tank.
13. If a science room is found to have rubber hose attachments that extend
below the sink rim, what immediate action should be taken to ensure safety?
Increase the water pressure to flush the system.
Remove the hose attachments to prevent backflow contamination.
Install a filtration system to clean the water.
Ignore the issue if no contamination is visible.
