DC 3RD CLASS TEST STATIONARY
BOILER ACTUAL EXAM 2025
LATEST PREP TEST BANK WITH 200
QUESTIONS AND DETAILED
VERIFIED ANSWERS JUST
RELEASED!
"During a 24 hours operation how often should you check the water level? - CORRECT ANSWER=>
once per shift"
"How often do you check the high limit switch? - CORRECT ANSWER=> Annually"
"What is the recommended time for a complete external inspection of a boiler? - CORRECT
ANSWER=> once per shift"
"What is the first thing to do when shutting down a boiler? - CORRECT ANSWER=> To turn off the
fire"
"A flow control should be blown down when? - CORRECT ANSWER=> once per shift"
"How often should you check the Low Water Fuel Cut off? - CORRECT ANSWER=> once per shift"
"Why is oil added to the refrigerant? - CORRECT ANSWER=> lubrication of the compressor
Keep refrigerant migrating"
"Recycled and filtered refrigerant can be used where? - CORRECT ANSWER=> By the same owner
in the same type of equipment"
1|Page
,"Data printed on the equipment nameplate would include manufacturer, model, and serial
number and________________? - CORRECT ANSWER=> Stamp of approval from commissioning
authority"
"How many BTU's does it take to raise 10 lbs of steam from 40 to 41 degrees? - CORRECT
ANSWER=> 1 BTU"
"When working on a boiler, permits should be required? - CORRECT ANSWER=> For every shift"
"How many things do safety controls protect against? - CORRECT ANSWER=> Over pressure
Over Heating
Fire side explosions"
"What chemical compounds in water cause permanent hardness? - CORRECT ANSWER=> Calcium
Sulfate and Magnesium Silicate"
"What chemicals are used to combat corrosion? - CORRECT ANSWER=> sodium sulfite and
hydrazine"
"You have boiler water that is found to have a PH of 5. What compound do you add to
neutralize? - CORRECT ANSWER=> bases"
"What produces soft scale? - CORRECT ANSWER=> calcium carbonate and magnesium carbonate"
"With normal oxygen and low alkalinity, what is added to boiler water? - CORRECT ANSWER=>
Neutralizing Amines"
"What is hard forming scale? - CORRECT ANSWER=> silica"
"Which chemicals are used to combat scale? - CORRECT ANSWER=> Combined Phosphate
Treatment"
"Which compound is not heat produce? - CORRECT ANSWER=> Nitrogen"
"What takes no actual action in combustion? - CORRECT ANSWER=> Nitrogen"
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, "With hydroxide present & normal oxygen levels; which chemical will cause problems? -
CORRECT ANSWER=> Chlorine"
"What mechanical device is used to remove scale from Fire Tubes? - CORRECT ANSWER=> A Tube
Rattler or Vibrator is used"
"Who can make Adjustments or repairs on a Safety Valve? - CORRECT ANSWER=> Qualify person
from Manufacturer or Representative"
"What mechanical device is used to remove scale from water Tubes? - CORRECT ANSWER=> A
Tube Turbine is used"
"In a duct air handling system, space thermostat control building temperatures by? - CORRECT
ANSWER=> Mixing the air from hot & cold duct in a mixing box serving the space"
"The removal of moisture from air using a cooling coil is called _________ dehumidification? -
CORRECT ANSWER=> Passive"
"In a multi-zone air handler unit, the zone thermostat controls the zone temperature by? -
CORRECT ANSWER=> Dampers that control the air flow from the hot & cold duct"
"An air handler unit that has hot & cold air ducts connected to (molding boxes?) located in each
building space is called a __________air handler unit? - CORRECT ANSWER=> dual duct"
"An air handler unit supplies a constant supply air temperature of 55 degree F to building
spaces and includes a coil called _____air handler unit? - CORRECT ANSWER=> terminal reheat"
"An air handler unit that provides heating, cooling, ventilation, and air conditioning to more
than one building or area and has its cooling & heating Coil in separate side-by side ducts is
called a _______air handling unit? - CORRECT ANSWER=> multi-zone"
"In a dual duct air handling system space thermostatic controls building temperature by? -
CORRECT ANSWER=> Moving the air from the hot & cold duct in a molding box serving the
space."
"A boiler is rated at (86,250 lbs, 88,250 lbs, 96,250 lbs) of steam per hour. What is the
equivalent boiler horsepower? - CORRECT ANSWER=> 2500 HP = 86,.5 = 2500 lbs"
3|Page
BOILER ACTUAL EXAM 2025
LATEST PREP TEST BANK WITH 200
QUESTIONS AND DETAILED
VERIFIED ANSWERS JUST
RELEASED!
"During a 24 hours operation how often should you check the water level? - CORRECT ANSWER=>
once per shift"
"How often do you check the high limit switch? - CORRECT ANSWER=> Annually"
"What is the recommended time for a complete external inspection of a boiler? - CORRECT
ANSWER=> once per shift"
"What is the first thing to do when shutting down a boiler? - CORRECT ANSWER=> To turn off the
fire"
"A flow control should be blown down when? - CORRECT ANSWER=> once per shift"
"How often should you check the Low Water Fuel Cut off? - CORRECT ANSWER=> once per shift"
"Why is oil added to the refrigerant? - CORRECT ANSWER=> lubrication of the compressor
Keep refrigerant migrating"
"Recycled and filtered refrigerant can be used where? - CORRECT ANSWER=> By the same owner
in the same type of equipment"
1|Page
,"Data printed on the equipment nameplate would include manufacturer, model, and serial
number and________________? - CORRECT ANSWER=> Stamp of approval from commissioning
authority"
"How many BTU's does it take to raise 10 lbs of steam from 40 to 41 degrees? - CORRECT
ANSWER=> 1 BTU"
"When working on a boiler, permits should be required? - CORRECT ANSWER=> For every shift"
"How many things do safety controls protect against? - CORRECT ANSWER=> Over pressure
Over Heating
Fire side explosions"
"What chemical compounds in water cause permanent hardness? - CORRECT ANSWER=> Calcium
Sulfate and Magnesium Silicate"
"What chemicals are used to combat corrosion? - CORRECT ANSWER=> sodium sulfite and
hydrazine"
"You have boiler water that is found to have a PH of 5. What compound do you add to
neutralize? - CORRECT ANSWER=> bases"
"What produces soft scale? - CORRECT ANSWER=> calcium carbonate and magnesium carbonate"
"With normal oxygen and low alkalinity, what is added to boiler water? - CORRECT ANSWER=>
Neutralizing Amines"
"What is hard forming scale? - CORRECT ANSWER=> silica"
"Which chemicals are used to combat scale? - CORRECT ANSWER=> Combined Phosphate
Treatment"
"Which compound is not heat produce? - CORRECT ANSWER=> Nitrogen"
"What takes no actual action in combustion? - CORRECT ANSWER=> Nitrogen"
2|Page
, "With hydroxide present & normal oxygen levels; which chemical will cause problems? -
CORRECT ANSWER=> Chlorine"
"What mechanical device is used to remove scale from Fire Tubes? - CORRECT ANSWER=> A Tube
Rattler or Vibrator is used"
"Who can make Adjustments or repairs on a Safety Valve? - CORRECT ANSWER=> Qualify person
from Manufacturer or Representative"
"What mechanical device is used to remove scale from water Tubes? - CORRECT ANSWER=> A
Tube Turbine is used"
"In a duct air handling system, space thermostat control building temperatures by? - CORRECT
ANSWER=> Mixing the air from hot & cold duct in a mixing box serving the space"
"The removal of moisture from air using a cooling coil is called _________ dehumidification? -
CORRECT ANSWER=> Passive"
"In a multi-zone air handler unit, the zone thermostat controls the zone temperature by? -
CORRECT ANSWER=> Dampers that control the air flow from the hot & cold duct"
"An air handler unit that has hot & cold air ducts connected to (molding boxes?) located in each
building space is called a __________air handler unit? - CORRECT ANSWER=> dual duct"
"An air handler unit supplies a constant supply air temperature of 55 degree F to building
spaces and includes a coil called _____air handler unit? - CORRECT ANSWER=> terminal reheat"
"An air handler unit that provides heating, cooling, ventilation, and air conditioning to more
than one building or area and has its cooling & heating Coil in separate side-by side ducts is
called a _______air handling unit? - CORRECT ANSWER=> multi-zone"
"In a dual duct air handling system space thermostatic controls building temperature by? -
CORRECT ANSWER=> Moving the air from the hot & cold duct in a molding box serving the
space."
"A boiler is rated at (86,250 lbs, 88,250 lbs, 96,250 lbs) of steam per hour. What is the
equivalent boiler horsepower? - CORRECT ANSWER=> 2500 HP = 86,.5 = 2500 lbs"
3|Page
