Schedule 80 pipe is required in a propane system:
for propane vapour under 125 psig (860 kPa) working pressure
when steel piping is to be connected to plastic piping
for propane vapour over 125 psig (860 kPa) working pressure
when copper piping is to be connected to plastic pipe
When sizing branch line, what is the maximum size a job fabricated welded fitting that can be used in a 6” NPS gas supply
6” NPS
3” NPS
4” NPS
2” NPS
Natural gas piping in industrial buildings shall be identified:
with yellow paint or yellow bands
with red paint or red bands
with paint in a contrasting colour to other pipes
with green paint and yellow bands
A panel-mounted ground fault circuit interrupting breaker protects all:
electrical loads in the circuits from that panel
loads in the circuit served by that breaker
240 volt circuits served by that breaker panel
120 volt circuits served by that breaker panel
Branch circuit fuse size is determined by the:
size of the wire
the length of the wire
voltage supplied to the appliance
type of insulation on the wire
The 24 volt control circuit supply for a residential gas furnace comes from a:
60/24 volt step down transformer
120/24 volt step down transformer
240/24 step down transformer
240/120 volt step down transformer
On an electrical schematic diagram, the safety controls are typically drawn:
to the right of the loads
above the loads
below the loads
to the left of the loads
The power supply to a residential gas furnace is:
120/1/60
120/2/60
240/1/60
240/2/60
As gauge number of a conductor increase, its current carrying capacity:
increases
decreases
remains the same
varies directly
As more circuits are added to a panel, the total current drawn from the panel:
Increases
fluctuates
A hard, sharp pilot flame indicates
the orifice is too small
there is a lack of air
there is excessive draft at the pilot location
high gas pressure
Direct current travels:
only from the load directly to the source
in one direction only
only from the source directly to the load
across the load only
A receptacle-mounted ground fault interrupter protects against:
appliance overload
dead shorts
short circuits
current flow to ground
On an electrical schematic, the system is shown with the:
disconnect closed with all devices as though the heating is on
disconnect closed with all devices as though there is a call for heating but the heating has not yet come on
disconnect open with all devices as though there is a call for heating
disconnect open with all devices as though there is no call for heating
The normal fuse size for #12 AWG copper wire is:
15 amps
20 amps
30 amps
40 amps
A zero ohmmeter reading taken between the casing of a solenoid and a disconnected wire to the solenoid indicates that:
the coil is good
the coil is shorted to the casing of the device
the coil wire is broken
all of the available choices
As the diameter of a conductor decreases, its resistance:
When can an on/off switch be installed in the neutral wire from an electrical panel to a gas furnace:
never
only when it carries 24 volts or less
only when the switch is 3 feet or less from the appliance
only when the supply is 240 volts
A thermostat with a single mercury bulb which controls a single stage heat, single stage cool unit is a ___________ control:
SPST (single pole single throw)
SPDT (single pole double throw)
DPST (single pole single throw)
DPDT (double pole double throw)
How tight should a thermocouple connection be:
finger tight
¼ turn past finger tight
1 ½ turns past finger tight
two turns with a wrench
What happens to the resistance inside an infrared scanner when the scanner is exposed to infrared radiation:
resistance increases
resistance decreases
resistance remains the same
resistance fluctuates
What is required combustion air inlet size for a stationary gas engine having an input of 1,800,000 Btuh installed in a room?
30 square inches (1,800 mm2)
60 square inches (3,900 mm2)
120 square inches (7,800 mm2)
180 square inches (11,600 mm2)
After correctly sizing an air intake opening, the grill or screen should cover the opening. What is the minimum size of the mesh on an air intake grill?
3/32” (2 mm)
1/8” (3 mm)
1/4” (6 mm)
1/2" (12 mm)
The most important element required for proper combustion in a gas appliance is:
carbon dioxide
air
nitrogen
water vapour
The best method of removing dust from a house is:
humidification
infiltration
filtration
exfiltration
To reduce heat loss, the most effective thing to do is to:
add attic insulation
install new windows
seal air leaks
install a heat recovery unit
The best way to remove odours from a house is to:
filter the air in the house
ventilate the house
install mechanical attic ventilation
humidify the air in the house
The maximum negative building pressure that a natural draft vented appliance should be exposed to is:
5 Pa (- 0.02” w.c.)
10 Pa (- 0.04” w.c.)
15 Pa (- 0.06” w.c.)
20 Pa (- 0.08” w.c.)
After a direct vent radiant heating system is installed in a new house, the customer complains that, “The walls and windows are wet.” From the following list, what is the most reasonable response?
after confirming the heat exchanger is not cracked, advise the customer to call for someone else
recommend that a window be left open a bit
advise the customer that the problem will disappear when the building dries out
recommend the installation of a mechanical ventilation system
Indoors in winter, if a vapour barrier has not been made continuous, the:
relative humidity will increase
relative humidity will decrease
heat gain will occur
heat loss will decrease
From the following list, which action will have the greatest effect on reducing mold growth in the house?
reducing relative humidity to approximately 10%
increasing relative humidity to approximately 80%
filtering the air in the house
covering earthen floors and open water surfaces
Which of the following actions will limit the problems caused by the “distribution effect” on conventional vented forced air furnaces?
seal the ductwork in the furnace area
balance the volume of return and supply air in each room or floor
ensure a tight seal around the furnace filter and blower door
Currently, the most common type of building construction is:
balloon
platform
double brick
solid brick
The main purpose of the building skin is to:
protect the underlying materials
reduce heat gain
improve resistance to vapour flow
maintain the depressurization limit
The “systems approach” as it applies to a building is a means of understanding how fuel-fired appliances affect and are affected by the:
outside environment
building
occupants
Which symbol represents a gas solenoid?
4
5
6
7
Which symbol represents the dryer heat thermostat?
1
2
3
Which symbol represents a dryer high limit switch?
Which symbol represents a dryer centrifugal switch?
Which symbol represents a dryer pilot switch?
Which symbol represents a timer motor?
The required clearance to combustible material above a pendant gas lamp is:
5 inches (125 mm)
12 inches (300 mm)
15 inches (375 mm)
18 inches (450 mm)
The mantle of a gas lamp:
provides ignition
mixes air and gas
protects the igniter
changes a blue flame to a luminous flame
What is the minimum clearance from the sides of a domestic range to combustible materials, unless otherwise specified?
1 inches (25 mm)
3 inches (75 mm)
6 inches (150 mm)
9 inches (225 mm)
What type of protection does a range require if it is certified for zero side clearance from combustible material?
28 MSG (0.3 mm) sheet metal spaced out 0.25 inch (6 mm)
28 MSG (0.3 mm) sheet metal applied directly to the combustible material
1/4 inch (6 mm) asbestos millboard
no protection required
The primary function of a surge arrestor in the top of a regulator is to:
allow the regulator to breath
reduce the opening speed of the regulator
limit the escape of gas to 1 cu. ft./hour
stop the regulator from operating if it is over pressurized
Propane containers located on the outside of a recreational vehicle shall be:
mounted securely to the roof of the vehicle
mounted on an “A” frame as close to the front of the vehicle as practicable
secured ahead of the front bumper
secured to the rear of the vehicle
A monitor regulator:
is a redundant regulator which backs up the operating regulator
controls gas flow to the top of the diaphragm
reduces pressure from pounds to ounces
remains locked off until it is required
What is the maximum outlet pressure for a first stage regulator on a residential propane system?
11.0” w.c.
11 psi
10.0 psi
15.0 psi
For appliances with the same input, the size of the orifice used for a propane appliance should be:
the same size as the orifice used for natural gas
larger than the orifice used for natural gas
smaller than the orifice used for natural gas
< 3% the size of the orifice used for natural gas
What does movement of 1/43 ft. dial indicate when completing a gas meter pressure dial test?
the service regulator is malfunctioning
the static pressure is excessive
the working pressure is low
the piping is not gas tight
What should be done if it is noticed that a regulator set in a loading dock area is not protected against physical damage?
advise the customer to provide protection as soon as possible
notify the local gas utility that protection is required
advise the customer to contact the local gas utility
report the situation to the Technical Standard and Safety Authority immediately
What is the maximum permitted filling density of a cylinder with liquid propane (relative density = 0.51) by liquid volume? (liquid temperature assumed to be 40°F ( 4.5°C)
42%
60%
80%
90%
What will happen if the adjusting screw of a regulator is turned counter-clockwise decreasing the spring pressure?
the downstream pressure will remain the same
the downstream pressure will decrease
the upstream pressure will increase
the upstream pressure will decrease
A regulator is sized for the load it is to serve by:
multiplying the appliance input by 1.5 and selecting a regulator in that input range
checking the appliance rating plate and selecting a regulator for that input range
determining the pipe size of the appliance manifold and selecting a regulator in that input range
multiplying the appliance input by 1.25 and selecting a regulator in that input range
Which of the following are used in an absorption refrigeration cycle?
ammonia and helium
ammonia and hydrogen
ammonia and propane
ammonia and butane
What are the main components of a gas-fired refrigerator?
generator, evaporator, radiator, absorber
generator, evaporator, capacitor, absorber
generator, evaporator, compressor, absorber
generator, evaporator, absorber, condenser
Is it permissible to use the propane side of a refrigerator in a recreation vehicle while the vehicle is in motion?
no
no, unless the vehicle is only being moved to a more level location
yes
yes, if the vehicle is being moved 1 mile or less
How can the location of a leak in a heat exchanger be determined?
by using a flue gas analyzer and visual examination
by using a carbon monoxide detector and visual examination
by using a smoke generator and visual examination
Why does the recommended range of CO2 in a conventional furnace differ from the ultimate amount of CO2 of 11.9%?
to provide a safety margin
to provide a higher efficiency
to maintain a neutral pressure point at the door catch
to maintain a low stack temperature
Net stack temperature is the flue gas temperature:
downstream of the draft hood
upstream of the draft hood
plus the ambient temperature
minus the ambient temperature
A forced draft burner has a blower that produces sufficient pressure to overcome the resistance of the:
burner
burner and the appliance
burner and the appliance downdraft
venting system
When the installation of an appliance constitutes a conversion from another form of energy to gas, the installer must:
advise the user in writing of the procedure to follow to discontinue the supply of the former form of energy
remove all aspects of the previous installation
remove the electrical supply wiring from the panel
advise the previous energy supplier of the change
When the required minimum clearance for a vent connector is 9” (228 mm) to combustible material with no protection, what is the acceptable method to reduce the clearance by 3” (76 mm)?
use 0.05” (12 mm) insulating millboard spaced out 0.05 (12 mm) with noncombustible spacers
use 0.25” (6 mm) insulating millboard spaced out 1” (25 mm)
use 22 gauge sheet metal attached to the hot side of the-combustible material
use 28 gauge sheet metal spaced out 1” (25 mm) from the combustible material
What will happen when the neutral pressure point for a conversion burner is improperly set?
the unit will overfire
the burner will short cycle
the burner efficiency will be affected
the burner will not fire
Gross stack temperature is the flue gas temperature
When using a gas detector such as a Drager or Gas Tec type, the most important aspect regarding the sample tube is that the:
detector is within the manufacturer’s date code
sample tube is within the manufacturer’s date code
detector has been inspected and verified
the sample tube is CGA approved
What is the minimum service clearance in front of a boiler?
18” (450 mm)
24” (600 mm)
36” (900 mm)
48” (1200 mm)
The high limit setting on a forced warm air converted furnace shall not exceed:
150°F (66°C)
200°F (90°C)
250°F (120°C)
350°F (180°C)
Increasing the burners air supply will have the following effect on the percentage of CO2 in the flue gases and stack temperature:
the percentage of CO2 will increase and the stack temperature will increase
the percentage of CO2 will decrease and the stack temperature will increase
the percentage of CO2 will decrease and the stack temperature will decrease
the percentage of CO2 will increase and the stack temperature will decrease
What is the minimum clearance to combustibles from the top of the plenum of a converted forced warm air furnace?
1” (25 mm)
3” (75 mm)
6” (150 mm)
12” (300 mm)
When using a flue gas analyzer, which measures CO2 and you are in doubt as to the accuracy of the reading, how would you verify the accuracy of the instrument?
by comparing it to a second sample
by comparing it to a known sample
by checking it against a gas meter test dial
by checking it against the appliance manufacturers maximum input rating
How far above the burner port does the centre line of the flue outlet have to be to convert a revertible flue furnace with a natural draft burner?
at least 6” (150 mm)
less than 12” (300 mm)
at least 12” (300 mm)
at least 24” (600 mm)
What will be the result if too large a fire pot is used in a converted furnace or boiler?
pulsation will occur
there will be poor efficiency
the limit control will be ineffective
the high limit switch will open
What is the minimum clearance to combustibles material from the sides of a converted boiler?
What should be done if a relief valve is leaking?
remove the valve and clean off the calcium deposits
replace the valve seat and check for the cause of the activation
replace the relief valve and check for the cause of the activation
open a tap and relieve the tank pressure until the flow stops at the relief valve
What is the pressure relief valve setting for most residential type water heaters?
75 psig (517 kPa)
100 psig (690 kPa)
150 psig (1034 kPa)
200 psig (1380 kPa)
From the following list, which is the best location for a combination heating system consisting of a water heater and air handler?
in the insulated but unheated attached garage
the water heater in the basement and the air handler in the attic
together in a central location in the basement
the air handler supported on top of a rear flue water heater in a closet space
Which of the controls listed below controls the gas pressure to the main burner, the temperature of the water, and turns off the gas when the pilot goes out?
E.C.O.
temperature and pressure relief valve
aquastat
unitrol
Combination systems are sized to deliver __________ of the calculated heat loss of the building.
95% to 105%
120%
200%
The recommended water temperature setting from a mixing valve to the domestic water system in combination heating systems that employ oil-fired water heaters for heating potable water and for space heating is:
43°C (110°F)
49°C to 54°C (120°F to 130°F)
60°C to 66°C (140°F to 150°F)
83°C (180°F)
The components of a copper fin tube, instantaneous water heater are a/an:
anti-scald device and a pump control
pump, pump control, flow switch, temperature/pressure relief valve, and a limit control
E.C.O., temperature and pressure relief valve, anode, and a dip tube
temperature and pressure relief valve, anode, and a limit control
The temperature of the water returning from the heating loop in a combination system employing a water heater for domestic hot water and space heating must be:
higher than the outlet temperature from the water heater
no more than 5°C (9°F) below the outlet temperature from the water heater
lower than the minimum temperature required to activate the burner
at least the set temperature of the domestic hot water supply
Describe the leak testing required when replacing an existing gas water heater.
soap or detection instrument using an inert gas using table 8.25.2 to determine test pressure and duration
soap or detection instrument at the normal working pressure
soap or detection instrument at 2 times the normal working pressure
soap or detection instrument and a 10 minute dial test or leak test at normal working pressure
The flow rate of water passing through a heating coil of an air handler is controlled by the:
aquastat on the water heater
balancing valve on the heating loop
mixing valve on the heating loop
mixing valve on the domestic hot water system
What will cause the E.C.O. to open?
a defective thermostat
long draws of water
a dip tube which is too short
too low a thermostat setting
When can combination-heating systems employing a water heater be attached to baseboards or radiators that were previously used for boiler heating?
always
only after being cleaned with muriatic acid
only after having been descaled
What type of water heater can be installed in a bathroom?
direct vent
power vent
fan assisted
revertible flue
What is the minimum required clearance from combustibles to the top, bottom, and sides of a horizontal furnace?
6”
5”
12”
18”
When is it permissible to store propane cylinders in the basement of a new home for future connection to a construction heater?
only when the hose is less than 10 feet long
only when a flex connector is used
Which instrument is used to determine the speed of a direct drive fan motor?
A voltmeter
A manometer
An anemometer
A tachometer
Which control will shut the gas flow off in a high efficiency furnace if the venter motor fails?
high limit switch
roll out switch
air proving switch
ignition switch
In a repair garage, an appliance shall be installed so that a component capable of igniting a flammable vapour is located at least ______________ above the floor.
2 feet (600 mm)
4.5 feet (1500 mm)
6 feet (2 m)
What is the minimum distance that the vent from a 75,000 Btuh Category III furnace may terminate from a door?
1 foot
3 feet
6 feet
10 feet
Before lighting a burner in a steam boiler, ensure that:
there is water in the boiler
the temperature controller is set properly
the main burner test firing valve is turned on
the safety valves are open
On seasonal start up, a pool heater should run:
intermittently
continuously for 24 hours
continuously until the thermostat is satisfied
one hour on and one hour off until the thermostat is satisfied
Automatic chlorinators must be installed:
upstream of the heater
downstream of the heater
upstream of the filter
downstream of the filter
If the thermostat heat anticipator is set to too low a setting:
the space temperature will be too high
the space temperature will be too low
the burner will run until the desired space temperature is achieved
the circulating pump will run continuously
Aquastats respond to changes in:
flue gas temperature
water temperature
stack temperature
air temperature
The external bypass valve is set by:
shutting off the pump
viewing the burner flame size
determining the appliance input
determining the temperature rise across the appliance
What safety control protects a steam boiler if the condensate pump fails to return water to the boiler?
high pressure limit control
low pressure limit control
flame safeguard control
low water cutoff
Condensate in a boiler heating system is:
water heated for use in restaurant equipment
water in a water boiler return line
water from the relief valve in a boiler
water in a steam boiler return line
A room heater installed in either a sleeping area or public area shall be:
direct vent only
equipped with a regulator
equipped with a fan
equipped with an on / off switch on the wall
Single wall vent connectors:
may pass through floors, ceilings or roofs provided a metal thimble is used
may pass through floors, ceilings or roofs provided the required minimum distance from combustible material is maintained
may pass through floors, ceilings or roofs provided they are insulated
shall not pass through floors, ceilings or roofs
An appliance vent shall terminate from any building mechanical air inlet by at least:
1 foot (300 mm)
3 feet (900 mm)
6 feet (1800 mm)
10 feet (3 m)
What material must be used for the vent connector on an appliance without flue gas dilution air?
22 B & SG (0.64 mm) aluminum
24 GSG (0.60 mm) galvanized steel
26 GSG (0.47 mm) galvanized steel
28 GSG (0.38 mm) galvanized steel
Which of the following statements is correct?
a draft hood will eliminate back drafts coming down the chimney
a draft hood will prevent a negative pressure inside the building
a draft hood will prevent a down draft from entering the appliance
a draft hood will prevent flue gases from entering a building
The function of a fixed draft hood is to ensure:
negative over fire draft
positive over fire draft
zero (neutral) over fire draft
variable over fire draft condition
When sizing either a vent or chimney which will vent more than one natural gas appliance, which of the following could be used in determining the size of the common vent?
the area of the common vent shall equal the total area of all the flue collars
the area of the common vent shall equal the area of the largest single flue collar
the area of the common vent shall equal the area of either the largest draft control device outlet or the largest flue outlet plus 50% of the sum of the outlet areas of the additional appliances
the area of the common vent shall equal the area of either the largest draft control device outlet or the largest flue outlet plus 75% of the sum of the outlet areas of the additional appliances
There is a new forced air furnace equipped with an induced draft fan beside a conventional water heater in a basement. The customer has decided to enclose the area to make a separate furnace room. The house is approximately 25 years old and has a door separating the basement from the upper levels. - Furnace input = 100,000 Btuh (8.1.2 and footnote) - AWH input = 25,000 Btuh - Enclosure = 10’ x 20’ x 7’ - Structure dimensions = 20’ x 30’ x 7’ x 3 (levels)
What size opening will be required in the furnace room door to provide sufficient combustion air from inside the home?
0 square inches
9 square inches
18 square inches
125 square inches
What size opening is required in the furnace room door to provide sufficient ventilation air for the furnace room?
8 square inches
Ventilation air openings for gas appliances should be located:
at the lowest possible point communicating with the outdoors
at the highest possible point communicating with the outdoors
on the same horizontal plane as the combustion air opening
at or above the level of the burner
A draft hood for an appliance shall be:
located in a different room than the appliance it serves
located in the same room as the appliance it serves
installed on an appliance with an induced draft
sized to the existing vent connection
“Spillage” of flue gases at the appliance draft diverter would indicate that:
an updraft condition is present in the venting system of the appliance
there is excessive draft at the appliance
the venting system of the appliance is restricted
the appliance is under fired
A boiler room contains the following natural draft appliances: - two hot water boilers, each firing at 750,000 Btuh - 1 water heater firing at 270,000 Btuh - 1 water heater firing at 30,000 Btuh
What is the minimum required combustion air opening?
100 square inches
200 square inches
900 square inches
1800 square inches
What is the minimum size required for the air supply opening given the information listed below?
All appliances are equipped with draft diverters, the building is of recent construction with close fitting windows and doors, vapour barrier and drywall and the total input of all appliances is 310,000 Btuh.
36 square inches (23000 mm2)
43 square inches (28000 mm2)
47 square inches (30000 mm2)
50 square inches (32000 mm2)
Which of the following instruments is used to check the pressure drop across an indoor coil?
a velometer
an inclined manometer
an anemometer
a psychrometer
What is the purpose of an air-proving switch in an electronic air cleaner?
it ensures the fan motor is running
it ensures the fan is running
it ensures the draft is correct
it ensures there is no negative air
What happens when the humidistat for a power humidifier closes?
the humidifier solenoid valve opens
the humidifier motor starts to turn
the furnace fan starts, then the humidifier starts
the gas valve opens the humidifier starts
How are electronic air cleaners wired?
in parallel with the fan motor
in series with the fan motor
in parallel with the fan
in series with the fan
Why is it important to position an electronic air cleaner correctly?
to ensure as much of the air is bypassed as is possible
to remove as many odours as possible
to ensure there is as much restriction to air flow as possible
to ensure an even distribution of air across the face of the filter
Plate humidifiers operate:
all the time the fan is running
only when the fan is on low speed
only when the fan is on high speed
only when the humidistat calls
The primary voltage for duct mounted electronic air cleaners is:
20 – 30 volts
120 – 130 volts
220 – 240 volts
9,000 – 12,000 volts
What is the most common transformer required for a power humidifier?
120 – 24 volt
240 - 24 volt
240 – 120 volt
120 – 240 volt
Heat which when added to or removed from a substance causes a change of temperature is:
superheat
specific heat
latent heat
sensible heat
Which device can be used to determine the restrictions in a duct system?
hydrometer
potentiometer
barometer
manometer
If the belt on a blower is too tight, the motor:
voltage will decrease
voltage will increase
current will decrease
current will increase
If the fan compartment door of an appliance is left off, the motor:
Where is the lowest air pressure in a forced warm air heating system?
in all ductwork
upstream of the blower
downstream of the blower
at the supply registers
Convection is:
heat transfer through solid objects
heat transfer through fluids
a wave form of heat transfer
a form of latent heat transfer
Increasing the size of a blower pulley:
increases air flow
decreases air flow
increases current flow
decreases temperature rise
A fan control:
shuts the blower off on safety only
starts the blower when the plenum is up to temperature
starts and stops the blower
ensures the burner will not start if overheating occurs
What is the minimum diameter of a pressure gauge needed to perform a leak test on gas piping?
2 in.
2 – 3/4 in.
3 in
3 – 1/2 in.
Ammeter’s can read what?
Pressure drop
Conductor magnetic field
Load in parallel wires
Direct power across loads
What are the millivolts power output on a closed circuit test?
20 to 30 mV
10 to 15 mV
2 to 4 mV
10 mV or less
A pilot with a lazy yellow flame would indicate?
Orifice too small
Mid to high gas pressure
Target pilot orifice
Orifice size too large
For flame rectification one of the most important things should be?
Flame molecules
Proper grounding plane
Proper air to gas mixture to pilot
Flame rod insulator
What makes a flame capillary sensor tube prove pilot to main gas valve?
Trial for ignition
Glow coil
Pilot flame
Intermittent pilot
Can a new installation of a fin type pool heater less than 250 MBtu be installed downstairs in a house?
Yes, if gas piping can support gas input
No
Yes, if pool heater is direct vented
Yes, if poll heater is close to chimney
When converting an oil furnace to gas what type of atmospheric burner can be used?
Burner tray
In shot
Ribbon burner
Primary air fan assist burner
If the flue gases are removed from the front of the appliance we could assume that it's a?
1 to 3 flue pass boiler
2 to 6 flue pass boiler
2 to 5 flue pass boiler
2 to 4 flue pass boiler
Can a gas log fireplace be installed in a sleeping quarter?
Yes, if proper air supply is added
Yes, if the venting is over sized
No, even if new venting is installed
Yes, only if its a bed sitting room
What is the minimum distance that a vent from an appliance with an input of 110 Mbtu/h can be from a non-mechanical air supply?
1 ft.
2 ft.
3 ft
6 ft.
On a pressuretrol, the main burner starts on?
Pressure rise
Water level
Pressure differential
Steam system output
On a hydronic heater system what control responds to a load change?
Low water cut off
Expansion tank
Flow switch
Aquastat
When installing propane tanks under 1,000 USWG, what would be the minimum distance from a building?
25 ft.
30 ft.
15 ft.
10 ft.
If an appliance is less than 83% efficient and non-positive it would be considered a?
Category II
Category I
Category IV
Category III
For a steam boiler, what would be the most important safety control?
Flame scanner
Flame roll out switch
High limit steam lock out control
For a low-pressure steam boiler what would be the maximum steam pressure setting?
30 psig
25 psig
10 psig
15 psig
How would you measure relative humidity?
Wet bulb and atmospheric pressure
Dry bulb and latent heat of vapour
Moisture bulb and wet bulb
Wet bulb and dry bulb
What is nitrogen known as?
Toxins
Explosive gases
Inert gas
Neutralizers
Which heat is removed or added to cause a change in state without change in temperature?
Sensible heat
Radiant heat
Latent heat
Super heat
Except when permitted, what is the minimum clearance to combustibles from the top of a gas refrigerator?
10 in.
36 in.
12 in
On a gas regulator, what controls the increase or decrease of gas flow to the appliance?
Restricting element
Vent hold
Loading element
Measuring element
When sizing capacitors in series, what would be the total capacitance (CT) using 12F and 15F capacitors?
5.66 CT
6.35 CT
6.97 CT
6.66 CT
What would be the Btu/h output of a 10 kW heater
38,210 Btu/h
36,220 Btu/h
33,150 Btu/h
34,120 Btu/h
Clocking a 5 cu ft. dial on a gas meter for 63 seconds, what would be the appliance input?
258 MBtu/h
286 MBtu/h
268 MBtu/h
284 MBtu/h
What does a gas pressure regulator control?
Inlet pressure
Gas flow
Downstream pressure
Locks out gas flow
A first stage or high-pressure regulator reduces tank pressure to...?
350 Psig to 10 Psig
375 Psig to 5 Psig
250 Psig to 10 Psig
375 Psig to 10 Psig
On a regulator, what senses outlet pressure?
Spring element
Which gas meter would be used for a small or mid size commercial installation?
Rotary type
Tubing type
Bellows type
Orifice
A bellows gas meter is also known as a?
Down stream displacement meter
Up stream displacement meter
Pressure displacement meter
Positive displacement meter
A fan assist burner is?
Designed for better combustion
Designed for conversion boiler
Designed to overcome appliance friction
Designed to overcome burner resistance
A propane service regulator would normally deliver pressure at
Pound to 11 in. w.c.
Ounces to 7 in. w.c.
Ounces to 11 in. w.c.
Pound to 7 in. w.c.
What monitors water flow in a pool heater?
Pressure switch
On a gas regulator, what is used to adjusts the outlet pressure?
Limiting orifice
Venting spillage can be caused by?
Improper combustion air mixture
Excessive elbows in venting system
Cracked heat exchanger
Blocked condensate furnace drain
When vent spillage occurs and flue gases pass back through the combustion zone, what change occurs?
Flue gases are hotter and rise faster through chimney
Flue CO2 gases are more efficient
Flue CO2 gases changes to N2
Flue CO2 gases changes to CO
For a freestanding propane range in a large kitchen, the flexible connector may be how long?
6 ft
4 ft.
8 ft. if range is in the center of the kitchen
An inverted sensor (measures water level) can be found operating what type of appliance?
Hot water boiler
Steam water boiler
Domestic hot water storage tank
Domestic potable hot water tank
What would be the input of a 0.60-gph-oil nozzle?
73 MBtu
70 MBtu
84 MBtu
50 MBtu
On a high efficiency furnace, what turns on the blower fan?
Klixon limit
Bi-metal switch
Relay timer
Temperature
A vent-limiting orifice is only allowed to approximately discharge how much gas in a 24-hour period?
1 cubic foot
10 cubic feet
20 cubic feet
24 cubic feet
What is the ultimate reading of CO2 (carbon dioxide) for natural gas?
9.9%
10.9%
11.9%
13.9%
What would be the approximate O2 (oxygen) reading?
9.0%
7.0%
5.0%
3.0%
What does a barometric damper control?
Excess Air
Pilot Air
Draft Air
Ventilation Air
A coil type boiler less than 400 MBtu would need a:
Spill switch and Low water cut off
Low water cut off and hi limit
Flow sensor and hi limit
Spill switch and hi limit
A portable infrared heater that cannot be interlocked shall be connected to a:
CO2 monitor alarm
CO monitor alarm
O2 monitor alarm
CO and O2 monitor alarm
On a decorative appliance with an H-shape burner, the carry over ports ensures:
Primary air mixture
Ignition of entire burner
Blue flame
Secondary air
The temperature of a high intensity infrared heater could reach up to:
1000°F
1800°F
1200°F
2025°F
Stack effect means?
Air flow though the appliance
Negative building pressure
Warm air will rise
External building envelope
What could be the problem if a domestic hot water tank dropped in temperature after five minutes of use?
Low gas input
Mixing valve
Broken dip tube
Gas valve
What is the minimum location from a property line that a pool heater can be installed?
24 in.
20 in.
18 in.
12 in.
Standard sizing for a circulating pump would be?
1 gpm per 2,000 Btu
3 gpm per 20,000 Btu
1 gpm per 1,000 Btu
1 gpm per 10,000 Btu
If you had a commercial air handler and needed to know the speed of the blower where the pulley on a five-horse power 3,450-rpm motor is 6-inch and the pulley on a two-inch-fifteen-foot drive shaft is 10-inch, what would be the rpm of the blower?
3450 rpm
2070 rpm
1725 rpm
863 rpm
What is the total diameter of a 4L-28 "V" drive belt?
280 in.
35 in.
28 in.
2.80 in.
What is the spark gap required for a spark ignitor?
1/4 to 3/8 in.
3/8 to 1/2 in.
1/16 to 3/16 in.
1/8 to 3/16 in
On a direct spark ignition control, what is the trial for ignition?
10 seconds
0.8 seconds
4 seconds
2 seconds
A pilotstat will de-energize after how many seconds?
90 seconds
What does a heat anticipator do?
Shuts the burner down if loss of gas supply
Determines the length of the burner "on" cycle
Acts as a back up safety limit
Shuts down burner on excess flow
Can NMD wire be installed to an outside gas lamp?
Yes
Only if the lamp is direct spark
Yes if it is 14 AWG wire
How many cubic feet of vapor will one pound of liquid propane (C3H8) expand to?
5.1 cu ft.
8.0 cu ft
7.5 cuft.
8.5 cu ft.
What does a spiral baffle do?
Remove flue gas
Speed up combustion
Slow flue gas
Raises flue temperature
When converting a furnace, how far above the burner must the flue collar be?
6 in.
8 in.
What would be the approximate time for purging a 1-inch NPS pipe at 100-feet?
50 seconds
1 minute
1 minute, 24 seconds
1 minute, 10 seconds
Natural gas is mostly made up of?
Methane and Butane
Methane and Ethane
Ethane and Butane
Butane and Propane
On a 14 /12 pitch roof, what would be the termination of a 5-inch B-Vent?
5 ft.
For a 20 horsepower steam boiler, what would be its maximum input in Btu?
200 Mbtu
530 Mbtu
680 Mbtu
700 Mbtu
On category IV appliances, can a single wall vent be used to vent flue gases?
Manufacturer approved only
Only if vents are silicone together
At what temperature do flue gases condensate?
125°F
127°F
129°F
130°F
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