G2 EXAM part 1

Question 1 of 200

1

Schedule 80 pipe is required in a propane system:

Select one of the following:

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

Explanation

Question 2 of 200

1

When sizing branch line, what is the maximum size a job fabricated welded fitting that can be used in a 6” NPS gas supply

Select one of the following:

6” NPS
3” NPS
4” NPS
2” NPS

Explanation

Question 3 of 200

1

Natural gas piping in industrial buildings shall be identified:

Select one of the following:

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

Explanation

Question 4 of 200

1

A panel-mounted ground fault circuit interrupting breaker protects all:

Select one of the following:

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

Explanation

Question 5 of 200

1

Branch circuit fuse size is determined by the:

Select one of the following:

size of the wire
the length of the wire
voltage supplied to the appliance
type of insulation on the wire

Explanation

Question 6 of 200

1

The 24 volt control circuit supply for a residential gas furnace comes from a:

Select one of the following:

60/24 volt step down transformer
120/24 volt step down transformer
240/24 step down transformer
240/120 volt step down transformer

Explanation

Question 7 of 200

1

On an electrical schematic diagram, the safety controls are typically drawn:

Select one of the following:

to the right of the loads
above the loads
below the loads
to the left of the loads

Explanation

Question 8 of 200

1

The power supply to a residential gas furnace is:

Select one of the following:

120/1/60
120/2/60
240/1/60
240/2/60

Explanation

Question 9 of 200

1

As gauge number of a conductor increase, its current carrying capacity:

Select one of the following:

increases
decreases
remains the same
varies directly

Explanation

Question 10 of 200

1

As more circuits are added to a panel, the total current drawn from the panel:

Select one of the following:

Increases
decreases
remains the same
fluctuates

Explanation

Question 11 of 200

1

A hard, sharp pilot flame indicates

Select one of the following:

the orifice is too small
there is a lack of air
there is excessive draft at the pilot location
high gas pressure

Explanation

Question 12 of 200

1

Direct current travels:

Select one of the following:

only from the load directly to the source
in one direction only
only from the source directly to the load
across the load only

Explanation

Question 13 of 200

1

A receptacle-mounted ground fault interrupter protects against:

Select one of the following:

appliance overload
dead shorts
short circuits
current flow to ground

Explanation

Question 14 of 200

1

On an electrical schematic, the system is shown with the:

Select one of the following:

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

Explanation

Question 15 of 200

1

The normal fuse size for #12 AWG copper wire is:

Select one of the following:

15 amps
20 amps
30 amps
40 amps

Explanation

Question 16 of 200

1

A zero ohmmeter reading taken between the casing of a solenoid and a disconnected wire to the solenoid indicates that:

Select one of the following:

the coil is good
the coil is shorted to the casing of the device
the coil wire is broken
all of the available choices

Explanation

Question 17 of 200

1

As the diameter of a conductor decreases, its resistance:

Select one of the following:

Increases
decreases
remains the same
varies directly

Explanation

Question 18 of 200

1

When can an on/off switch be installed in the neutral wire from an electrical panel to a gas furnace:

Select one of the following:

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

Explanation

Question 19 of 200

1

A thermostat with a single mercury bulb which controls a single stage heat, single stage cool unit is a ___________ control:

Select one of the following:

SPST (single pole single throw)
SPDT (single pole double throw)
DPST (single pole single throw)
DPDT (double pole double throw)

Explanation

Question 20 of 200

1

How tight should a thermocouple connection be:

Select one of the following:

finger tight
¼ turn past finger tight
1 ½ turns past finger tight
two turns with a wrench

Explanation

Question 21 of 200

1

What happens to the resistance inside an infrared scanner when the scanner is exposed to infrared radiation:

Select one of the following:

resistance increases
resistance decreases
resistance remains the same
resistance fluctuates

Explanation

Question 22 of 200

1

What is required combustion air inlet size for a stationary gas engine having an input of 1,800,000 Btuh installed in a room?

Select one of the following:

30 square inches (1,800 mm2)
60 square inches (3,900 mm2)
120 square inches (7,800 mm2)
180 square inches (11,600 mm2)

Explanation

Question 23 of 200

1

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?

Select one of the following:

3/32” (2 mm)
1/8” (3 mm)
1/4” (6 mm)
1/2" (12 mm)

Explanation

Question 24 of 200

1

The most important element required for proper combustion in a gas appliance is:

Select one of the following:

carbon dioxide
air
nitrogen
water vapour

Explanation

Question 25 of 200

1

The best method of removing dust from a house is:

Select one of the following:

humidification
infiltration
filtration
exfiltration

Explanation

Question 26 of 200

1

To reduce heat loss, the most effective thing to do is to:

Select one of the following:

add attic insulation
install new windows
seal air leaks
install a heat recovery unit

Explanation

Question 27 of 200

1

The best way to remove odours from a house is to:

Select one of the following:

filter the air in the house
ventilate the house
install mechanical attic ventilation
humidify the air in the house

Explanation

Question 28 of 200

1

The maximum negative building pressure that a natural draft vented appliance should be exposed to is:

Select one of the following:

5 Pa (- 0.02” w.c.)
10 Pa (- 0.04” w.c.)
15 Pa (- 0.06” w.c.)
20 Pa (- 0.08” w.c.)

Explanation

Question 29 of 200

1

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?

Select one of the following:

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

Explanation

Question 30 of 200

1

Indoors in winter, if a vapour barrier has not been made continuous, the:

Select one of the following:

relative humidity will increase
relative humidity will decrease
heat gain will occur
heat loss will decrease

Explanation

Question 31 of 200

1

From the following list, which action will have the greatest effect on reducing mold growth in the house?

Select one of the following:

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

Explanation

Question 32 of 200

1

Which of the following actions will limit the problems caused by the “distribution effect” on conventional vented forced air furnaces?

Select one of the following:

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
all of the available choices

Explanation

Question 33 of 200

1

Currently, the most common type of building construction is:

Select one of the following:

balloon
platform
double brick
solid brick

Explanation

Question 34 of 200

1

The main purpose of the building skin is to:

Select one of the following:

protect the underlying materials
reduce heat gain
improve resistance to vapour flow
maintain the depressurization limit

Explanation

Question 35 of 200

1

The “systems approach” as it applies to a building is a means of understanding how fuel-fired appliances affect and are affected by the:

Select one of the following:

outside environment
building
occupants
all of the available choices

Explanation

Question 36 of 200

1

Which symbol represents a gas solenoid?

Select one of the following:

4
5
6
7

Explanation

Question 37 of 200

1

Which symbol represents the dryer heat thermostat?

Select one of the following:

1
2
3
4

Explanation

Question 38 of 200

1

Which symbol represents a dryer high limit switch?

Select one of the following:

1
3
4
7

Explanation

Question 39 of 200

1

Which symbol represents a dryer centrifugal switch?

Select one of the following:

1
4
6
7

Explanation

Question 40 of 200

1

Which symbol represents a dryer pilot switch?

Select one of the following:

1
2
3
7

Explanation

Question 41 of 200

1

Which symbol represents a timer motor?

Select one of the following:

4
5
6
7

Explanation

Question 42 of 200

1

The required clearance to combustible material above a pendant gas lamp is:

Select one of the following:

5 inches (125 mm)
12 inches (300 mm)
15 inches (375 mm)
18 inches (450 mm)

Explanation

Question 43 of 200

1

The mantle of a gas lamp:

Select one of the following:

provides ignition
mixes air and gas
protects the igniter
changes a blue flame to a luminous flame

Explanation

Question 44 of 200

1

What is the minimum clearance from the sides of a domestic range to combustible materials, unless otherwise specified?

Select one of the following:

1 inches (25 mm)
3 inches (75 mm)
6 inches (150 mm)
9 inches (225 mm)

Explanation

Question 45 of 200

1

What type of protection does a range require if it is certified for zero side clearance from combustible material?

Select one of the following:

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

Explanation

Question 46 of 200

1

The primary function of a surge arrestor in the top of a regulator is to:

Select one of the following:

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

Explanation

Question 47 of 200

1

Propane containers located on the outside of a recreational vehicle shall be:

Select one of the following:

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

Explanation

Question 48 of 200

1

A monitor regulator:

Select one of the following:

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

Explanation

Question 49 of 200

1

What is the maximum outlet pressure for a first stage regulator on a residential propane system?

Select one of the following:

11.0” w.c.
11 psi
10.0 psi
15.0 psi

Explanation

Question 50 of 200

1

For appliances with the same input, the size of the orifice used for a propane appliance should be:

Select one of the following:

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

Explanation

Question 51 of 200

1

What does movement of 1/43 ft. dial indicate when completing a gas meter pressure dial test?

Select one of the following:

the service regulator is malfunctioning
the static pressure is excessive
the working pressure is low
the piping is not gas tight

Explanation

Question 52 of 200

1

What should be done if it is noticed that a regulator set in a loading dock area is not protected against physical damage?

Select one of the following:

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

Explanation

Question 53 of 200

1

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)

Select one of the following:

42%
60%
80%
90%

Explanation

Question 54 of 200

1

What will happen if the adjusting screw of a regulator is turned counter-clockwise decreasing the spring pressure?

Select one of the following:

the downstream pressure will remain the same
the downstream pressure will decrease
the upstream pressure will increase
the upstream pressure will decrease

Explanation

Question 55 of 200

1

A regulator is sized for the load it is to serve by:

Select one of the following:

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

Explanation

Question 56 of 200

1

Which of the following are used in an absorption refrigeration cycle?

Select one of the following:

ammonia and helium
ammonia and hydrogen
ammonia and propane
ammonia and butane

Explanation

Question 57 of 200

1

What are the main components of a gas-fired refrigerator?

Select one of the following:

generator, evaporator, radiator, absorber
generator, evaporator, capacitor, absorber
generator, evaporator, compressor, absorber
generator, evaporator, absorber, condenser

Explanation

Question 58 of 200

1

Is it permissible to use the propane side of a refrigerator in a recreation vehicle while the vehicle is in motion?

Select one of the following:

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

Explanation

Question 59 of 200

1

How can the location of a leak in a heat exchanger be determined?

Select one of the following:

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
all of the available choices

Explanation

Question 60 of 200

1

Why does the recommended range of CO2 in a conventional furnace differ from the ultimate amount of CO2 of 11.9%?

Select one of the following:

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

Explanation

Question 61 of 200

1

Net stack temperature is the flue gas temperature:

Select one of the following:

downstream of the draft hood
upstream of the draft hood
plus the ambient temperature
minus the ambient temperature

Explanation

Question 62 of 200

1

A forced draft burner has a blower that produces sufficient pressure to overcome the resistance of the:

Select one of the following:

burner
burner and the appliance
burner and the appliance downdraft
venting system

Explanation

Question 63 of 200

1

When the installation of an appliance constitutes a conversion from another form of energy to gas, the installer must:

Select one of the following:

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

Explanation

Question 64 of 200

1

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)?

Select one of the following:

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

Explanation

Question 65 of 200

1

What will happen when the neutral pressure point for a conversion burner is improperly set?

Select one of the following:

the unit will overfire
the burner will short cycle
the burner efficiency will be affected
the burner will not fire

Explanation

Question 66 of 200

1

Gross stack temperature is the flue gas temperature

Select one of the following:

downstream of the draft hood
upstream of the draft hood
plus the ambient temperature
minus the ambient temperature

Explanation

Question 67 of 200

1

When using a gas detector such as a Drager or Gas Tec type, the most important aspect regarding the sample tube is that the:

Select one of the following:

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

Explanation

Question 68 of 200

1

What is the minimum service clearance in front of a boiler?

Select one of the following:

18” (450 mm)
24” (600 mm)
36” (900 mm)
48” (1200 mm)

Explanation

Question 69 of 200

1

The high limit setting on a forced warm air converted furnace shall not exceed:

Select one of the following:

150°F (66°C)
200°F (90°C)
250°F (120°C)
350°F (180°C)

Explanation

Question 70 of 200

1

Increasing the burners air supply will have the following effect on the percentage of CO2 in the flue gases and stack temperature:

Select one of the following:

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

Explanation

Question 71 of 200

1

What is the minimum clearance to combustibles from the top of the plenum of a converted forced warm air furnace?

Select one of the following:

1” (25 mm)
3” (75 mm)
6” (150 mm)
12” (300 mm)

Explanation

Question 72 of 200

1

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?

Select one of the following:

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

Explanation

Question 73 of 200

1

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?

Select one of the following:

at least 6” (150 mm)
less than 12” (300 mm)
at least 12” (300 mm)
at least 24” (600 mm)

Explanation

Question 74 of 200

1

What will be the result if too large a fire pot is used in a converted furnace or boiler?

Select one of the following:

pulsation will occur
there will be poor efficiency
the limit control will be ineffective
the high limit switch will open

Explanation

Question 75 of 200

1

What is the minimum clearance to combustibles material from the sides of a converted boiler?

Select one of the following:

3” (75 mm)
6” (150 mm)
12” (300 mm)
18” (450 mm)

Explanation

Question 76 of 200

1

What should be done if a relief valve is leaking?

Select one of the following:

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

Explanation

Question 77 of 200

1

What is the pressure relief valve setting for most residential type water heaters?

Select one of the following:

75 psig (517 kPa)
100 psig (690 kPa)
150 psig (1034 kPa)
200 psig (1380 kPa)

Explanation

Question 78 of 200

1

From the following list, which is the best location for a combination heating system consisting of a water heater and air handler?

Select one of the following:

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

Explanation

Question 79 of 200

1

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?

Select one of the following:

E.C.O.
temperature and pressure relief valve
aquastat
unitrol

Explanation

Question 80 of 200

1

Combination systems are sized to deliver __________ of the calculated heat loss of the building.

Select one of the following:

90%
95% to 105%
120%
200%

Explanation

Question 81 of 200

1

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:

Select one of the following:

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)

Explanation

Question 82 of 200

1

The components of a copper fin tube, instantaneous water heater are a/an:

Select one of the following:

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

Explanation

Question 83 of 200

1

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:

Select one of the following:

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

Explanation

Question 84 of 200

1

Describe the leak testing required when replacing an existing gas water heater.

Select one of the following:

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

Explanation

Question 85 of 200

1

The flow rate of water passing through a heating coil of an air handler is controlled by the:

Select one of the following:

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

Explanation

Question 86 of 200

1

What will cause the E.C.O. to open?

Select one of the following:

a defective thermostat
long draws of water
a dip tube which is too short
too low a thermostat setting

Explanation

Question 87 of 200

1

When can combination-heating systems employing a water heater be attached to baseboards or radiators that were previously used for boiler heating?

Select one of the following:

always
never
only after being cleaned with muriatic acid
only after having been descaled

Explanation

Question 88 of 200

1

What type of water heater can be installed in a bathroom?

Select one of the following:

direct vent
power vent
fan assisted
revertible flue

Explanation

Question 89 of 200

1

What is the minimum required clearance from combustibles to the top, bottom, and sides of a horizontal furnace?

Select one of the following:

6”
5”
12”
18”

Explanation

Question 90 of 200

1

When is it permissible to store propane cylinders in the basement of a new home for future connection to a construction heater?

Select one of the following:

always
never
only when the hose is less than 10 feet long
only when a flex connector is used

Explanation

Question 91 of 200

1

Which instrument is used to determine the speed of a direct drive fan motor?

Select one of the following:

A voltmeter
A manometer
An anemometer
A tachometer

Explanation

Question 92 of 200

1

Which control will shut the gas flow off in a high efficiency furnace if the venter motor fails?

Select one of the following:

high limit switch
roll out switch
air proving switch
ignition switch

Explanation

Question 93 of 200

1

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.

Select one of the following:

18 inches (450 mm)
2 feet (600 mm)
4.5 feet (1500 mm)
6 feet (2 m)

Explanation

Question 94 of 200

1

What is the minimum distance that the vent from a 75,000 Btuh Category III furnace may terminate from a door?

Select one of the following:

1 foot
3 feet
6 feet
10 feet

Explanation

Question 95 of 200

1

Before lighting a burner in a steam boiler, ensure that:

Select one of the following:

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

Explanation

Question 96 of 200

1

On seasonal start up, a pool heater should run:

Select one of the following:

intermittently
continuously for 24 hours
continuously until the thermostat is satisfied
one hour on and one hour off until the thermostat is satisfied

Explanation

Question 97 of 200

1

Automatic chlorinators must be installed:

Select one of the following:

upstream of the heater
downstream of the heater
upstream of the filter
downstream of the filter

Explanation

Question 98 of 200

1

If the thermostat heat anticipator is set to too low a setting:

Select one of the following:

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

Explanation

Question 99 of 200

1

Aquastats respond to changes in:

Select one of the following:

flue gas temperature
water temperature
stack temperature
air temperature

Explanation

Question 100 of 200

1

The external bypass valve is set by:

Select one of the following:

shutting off the pump
viewing the burner flame size
determining the appliance input
determining the temperature rise across the appliance

Explanation

Question 101 of 200

1

What safety control protects a steam boiler if the condensate pump fails to return water to the boiler?

Select one of the following:

high pressure limit control
low pressure limit control
flame safeguard control
low water cutoff

Explanation

Question 102 of 200

1

Condensate in a boiler heating system is:

Select one of the following:

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

Explanation

Question 103 of 200

1

A room heater installed in either a sleeping area or public area shall be:

Select one of the following:

direct vent only
equipped with a regulator
equipped with a fan
equipped with an on / off switch on the wall

Explanation

Question 104 of 200

1

Single wall vent connectors:

Select one of the following:

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

Explanation

Question 105 of 200

1

An appliance vent shall terminate from any building mechanical air inlet by at least:

Select one of the following:

1 foot (300 mm)
3 feet (900 mm)
6 feet (1800 mm)
10 feet (3 m)

Explanation

Question 106 of 200

1

What material must be used for the vent connector on an appliance without flue gas dilution air?

Select one of the following:

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

Explanation

Question 107 of 200

1

Which of the following statements is correct?

Select one of the following:

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

Explanation

Question 108 of 200

1

The function of a fixed draft hood is to ensure:

Select one of the following:

negative over fire draft
positive over fire draft
zero (neutral) over fire draft
variable over fire draft condition

Explanation

Question 109 of 200

1

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?

Select one of the following:

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

Explanation

Question 110 of 200

1

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?

Select one of the following:

0 square inches
9 square inches
18 square inches
125 square inches

Explanation

Question 111 of 200

1

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 is required in the furnace room door to provide sufficient ventilation air for the furnace room?

Select one of the following:

0 square inches
8 square inches
18 square inches
125 square inches

Explanation

Question 112 of 200

1

Ventilation air openings for gas appliances should be located:

Select one of the following:

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

Explanation

Question 113 of 200

1

A draft hood for an appliance shall be:

Select one of the following:

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

Explanation

Question 114 of 200

1

“Spillage” of flue gases at the appliance draft diverter would indicate that:

Select one of the following:

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

Explanation

Question 115 of 200

1

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?

Select one of the following:

100 square inches
200 square inches
900 square inches
1800 square inches

Explanation

Question 116 of 200

1

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.

Select one of the following:

36 square inches (23000 mm2)
43 square inches (28000 mm2)
47 square inches (30000 mm2)
50 square inches (32000 mm2)

Explanation

Question 117 of 200

1

Which of the following instruments is used to check the pressure drop across an indoor coil?

Select one of the following:

a velometer
an inclined manometer
an anemometer
a psychrometer

Explanation

Question 118 of 200

1

What is the purpose of an air-proving switch in an electronic air cleaner?

Select one of the following:

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

Explanation

Question 119 of 200

1

What happens when the humidistat for a power humidifier closes?

Select one of the following:

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

Explanation

Question 120 of 200

1

How are electronic air cleaners wired?

Select one of the following:

in parallel with the fan motor
in series with the fan motor
in parallel with the fan
in series with the fan

Explanation

Question 121 of 200

1

Why is it important to position an electronic air cleaner correctly?

Select one of the following:

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

Explanation

Question 122 of 200

1

Plate humidifiers operate:

Select one of the following:

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

Explanation

Question 123 of 200

1

The primary voltage for duct mounted electronic air cleaners is:

Select one of the following:

20 – 30 volts
120 – 130 volts
220 – 240 volts
9,000 – 12,000 volts

Explanation

Question 124 of 200

1

What is the most common transformer required for a power humidifier?

Select one of the following:

120 – 24 volt
240 - 24 volt
240 – 120 volt
120 – 240 volt

Explanation

Question 125 of 200

1

Heat which when added to or removed from a substance causes a change of temperature is:

Select one of the following:

superheat
specific heat
latent heat
sensible heat

Explanation

Question 126 of 200

1

Which device can be used to determine the restrictions in a duct system?

Select one of the following:

hydrometer
potentiometer
barometer
manometer

Explanation

Question 127 of 200

1

If the belt on a blower is too tight, the motor:

Select one of the following:

voltage will decrease
voltage will increase
current will decrease
current will increase

Explanation

Question 128 of 200

1

If the fan compartment door of an appliance is left off, the motor:

Select one of the following:

voltage will decrease
voltage will increase
current will decrease
current will increase

Explanation

Question 129 of 200

1

Where is the lowest air pressure in a forced warm air heating system?

Select one of the following:

in all ductwork
upstream of the blower
downstream of the blower
at the supply registers

Explanation

Question 130 of 200

1

Convection is:

Select one of the following:

heat transfer through solid objects
heat transfer through fluids
a wave form of heat transfer
a form of latent heat transfer

Explanation

Question 131 of 200

1

Increasing the size of a blower pulley:

Select one of the following:

increases air flow
decreases air flow
increases current flow
decreases temperature rise

Explanation

Question 132 of 200

1

A fan control:

Select one of the following:

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

Explanation

Question 133 of 200

1

What is the minimum diameter of a pressure gauge needed to perform a leak test on gas piping?

Select one of the following:

2 in.
2 – 3/4 in.
3 in
3 – 1/2 in.

Explanation

Question 134 of 200

1

Ammeter’s can read what?

Select one of the following:

Pressure drop
Conductor magnetic field
Load in parallel wires
Direct power across loads

Explanation

Question 135 of 200

1

What are the millivolts power output on a closed circuit test?

Select one of the following:

20 to 30 mV
10 to 15 mV
2 to 4 mV
10 mV or less

Explanation

Question 136 of 200

1

A pilot with a lazy yellow flame would indicate?

Select one of the following:

Orifice too small
Mid to high gas pressure
Target pilot orifice
Orifice size too large

Explanation

Question 137 of 200

1

For flame rectification one of the most important things should be?

Select one of the following:

Flame molecules
Proper grounding plane
Proper air to gas mixture to pilot
Flame rod insulator

Explanation

Question 138 of 200

1

What makes a flame capillary sensor tube prove pilot to main gas valve?

Select one of the following:

Trial for ignition
Glow coil
Pilot flame
Intermittent pilot

Explanation

Question 139 of 200

1

Can a new installation of a fin type pool heater less than 250 MBtu be installed downstairs in a house?

Select one of the following:

Yes, if gas piping can support gas input
No
Yes, if pool heater is direct vented
Yes, if poll heater is close to chimney

Explanation

Question 140 of 200

1

When converting an oil furnace to gas what type of atmospheric burner can be used?

Select one of the following:

Burner tray
In shot
Ribbon burner
Primary air fan assist burner

Explanation

Question 141 of 200

1

If the flue gases are removed from the front of the appliance we could assume that it's a?

Select one of the following:

1 to 3 flue pass boiler
2 to 6 flue pass boiler
2 to 5 flue pass boiler
2 to 4 flue pass boiler

Explanation

Question 142 of 200

1

Can a gas log fireplace be installed in a sleeping quarter?

Select one of the following:

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

Explanation

Question 143 of 200

1

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?

Select one of the following:

1 ft.
2 ft.
3 ft
6 ft.

Explanation

Question 144 of 200

1

On a pressuretrol, the main burner starts on?

Select one of the following:

Pressure rise
Water level
Pressure differential
Steam system output

Explanation

Question 145 of 200

1

On a hydronic heater system what control responds to a load change?

Select one of the following:

Low water cut off
Expansion tank
Flow switch
Aquastat

Explanation

Question 146 of 200

1

When installing propane tanks under 1,000 USWG, what would be the minimum distance from a building?

Select one of the following:

25 ft.
30 ft.
15 ft.
10 ft.

Explanation

Question 147 of 200

1

If an appliance is less than 83% efficient and non-positive it would be considered a?

Select one of the following:

Category II
Category I
Category IV
Category III

Explanation

Question 148 of 200

1

For a steam boiler, what would be the most important safety control?

Select one of the following:

Flame scanner
Flame roll out switch
Low water cut off
High limit steam lock out control

Explanation

Question 149 of 200

1

For a low-pressure steam boiler what would be the maximum steam pressure setting?

Select one of the following:

30 psig
25 psig
10 psig
15 psig

Explanation

Question 150 of 200

1

How would you measure relative humidity?

Select one of the following:

Wet bulb and atmospheric pressure
Dry bulb and latent heat of vapour
Moisture bulb and wet bulb
Wet bulb and dry bulb

Explanation

Question 151 of 200

1

What is nitrogen known as?

Select one of the following:

Toxins
Explosive gases
Inert gas
Neutralizers

Explanation

Question 152 of 200

1

Which heat is removed or added to cause a change in state without change in temperature?

Select one of the following:

Sensible heat
Radiant heat
Latent heat
Super heat

Explanation

Question 153 of 200

1

Except when permitted, what is the minimum clearance to combustibles from the top of a gas refrigerator?

Select one of the following:

2 in.
10 in.
36 in.
12 in

Explanation

Question 154 of 200

1

On a gas regulator, what controls the increase or decrease of gas flow to the appliance?

Select one of the following:

Restricting element
Vent hold
Loading element
Measuring element

Explanation

Question 155 of 200

1

When sizing capacitors in series, what would be the total capacitance (CT) using 12F and 15F capacitors?

Select one of the following:

5.66 CT
6.35 CT
6.97 CT
6.66 CT

Explanation

Question 156 of 200

1

What would be the Btu/h output of a 10 kW heater

Select one of the following:

38,210 Btu/h
36,220 Btu/h
33,150 Btu/h
34,120 Btu/h

Explanation

Question 157 of 200

1

Clocking a 5 cu ft. dial on a gas meter for 63 seconds, what would be the appliance input?

Select one of the following:

258 MBtu/h
286 MBtu/h
268 MBtu/h
284 MBtu/h

Explanation

Question 158 of 200

1

What does a gas pressure regulator control?

Select one of the following:

Inlet pressure
Gas flow
Downstream pressure
Locks out gas flow

Explanation

Question 159 of 200

1

A first stage or high-pressure regulator reduces tank pressure to...?

Select one of the following:

350 Psig to 10 Psig
375 Psig to 5 Psig
250 Psig to 10 Psig
375 Psig to 10 Psig

Explanation

Question 160 of 200

1

On a regulator, what senses outlet pressure?

Select one of the following:

Restricting element
Measuring element
Loading element
Spring element

Explanation

Question 161 of 200

1

Which gas meter would be used for a small or mid size commercial installation?

Select one of the following:

Rotary type
Tubing type
Bellows type
Orifice

Explanation

Question 162 of 200

1

A bellows gas meter is also known as a?

Select one of the following:

Down stream displacement meter
Up stream displacement meter
Pressure displacement meter
Positive displacement meter

Explanation

Question 163 of 200

1

A fan assist burner is?

Select one of the following:

Designed for better combustion
Designed for conversion boiler
Designed to overcome appliance friction
Designed to overcome burner resistance

Explanation

Question 164 of 200

1

A propane service regulator would normally deliver pressure at

Select one of the following:

Pound to 11 in. w.c.
Ounces to 7 in. w.c.
Ounces to 11 in. w.c.
Pound to 7 in. w.c.

Explanation

Question 165 of 200

1

What monitors water flow in a pool heater?

Select one of the following:

Aquastat
Low water cut off
Pressure switch
Flow switch

Explanation

Question 166 of 200

1

On a gas regulator, what is used to adjusts the outlet pressure?

Select one of the following:

Restricting element
Loading element
Limiting orifice
Measuring element

Explanation

Question 167 of 200

1

Venting spillage can be caused by?

Select one of the following:

Improper combustion air mixture
Excessive elbows in venting system
Cracked heat exchanger
Blocked condensate furnace drain

Explanation

Question 168 of 200

1

When vent spillage occurs and flue gases pass back through the combustion zone, what change occurs?

Select one of the following:

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

Explanation

Question 169 of 200

1

For a freestanding propane range in a large kitchen, the flexible connector may be how long?

Select one of the following:

10 ft.
6 ft
4 ft.
8 ft. if range is in the center of the kitchen

Explanation

Question 170 of 200

1

An inverted sensor (measures water level) can be found operating what type of appliance?

Select one of the following:

Hot water boiler
Steam water boiler
Domestic hot water storage tank
Domestic potable hot water tank

Explanation

Question 171 of 200

1

What would be the input of a 0.60-gph-oil nozzle?

Select one of the following:

73 MBtu
70 MBtu
84 MBtu
50 MBtu

Explanation

Question 172 of 200

1

On a high efficiency furnace, what turns on the blower fan?

Select one of the following:

Klixon limit
Bi-metal switch
Relay timer
Temperature

Explanation

Question 173 of 200

1

A vent-limiting orifice is only allowed to approximately discharge how much gas in a 24-hour period?

Select one of the following:

1 cubic foot
10 cubic feet
20 cubic feet
24 cubic feet

Explanation

Question 174 of 200

1

What is the ultimate reading of CO2 (carbon dioxide) for natural gas?

Select one of the following:

9.9%
10.9%
11.9%
13.9%

Explanation

Question 175 of 200

1

What would be the approximate O2 (oxygen) reading?

Select one of the following:

9.0%
7.0%
5.0%
3.0%

Explanation

Question 176 of 200

1

What does a barometric damper control?

Select one of the following:

Excess Air
Pilot Air
Draft Air
Ventilation Air

Explanation

Question 177 of 200

1

A coil type boiler less than 400 MBtu would need a:

Select one of the following:

Spill switch and Low water cut off
Low water cut off and hi limit
Flow sensor and hi limit
Spill switch and hi limit

Explanation

Question 178 of 200

1

A portable infrared heater that cannot be interlocked shall be connected to a:

Select one of the following:

CO2 monitor alarm
CO monitor alarm
O2 monitor alarm
CO and O2 monitor alarm

Explanation

Question 179 of 200

1

On a decorative appliance with an H-shape burner, the carry over ports ensures:

Select one of the following:

Primary air mixture
Ignition of entire burner
Blue flame
Secondary air

Explanation

Question 180 of 200

1

The temperature of a high intensity infrared heater could reach up to:

Select one of the following:

1000°F
1800°F
1200°F
2025°F

Explanation

Question 181 of 200

1

Stack effect means?

Select one of the following:

Air flow though the appliance
Negative building pressure
Warm air will rise
External building envelope

Explanation

Question 182 of 200

1

What could be the problem if a domestic hot water tank dropped in temperature after five minutes of use?

Select one of the following:

Low gas input
Mixing valve
Broken dip tube
Gas valve

Explanation

Question 183 of 200

1

What is the minimum location from a property line that a pool heater can be installed?

Select one of the following:

24 in.
20 in.
18 in.
12 in.

Explanation

Question 184 of 200

1

Standard sizing for a circulating pump would be?

Select one of the following:

1 gpm per 2,000 Btu
3 gpm per 20,000 Btu
1 gpm per 1,000 Btu
1 gpm per 10,000 Btu

Explanation

Question 185 of 200

1

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?

	Created by toan nguyen over 4 years ago

Quiz on G2 EXAM part 1, created by toan nguyen on 08/02/2022.

G2 EXAM part 1

Question 1 of 200

Schedule 80 pipe is required in a propane system:

Select one of the following:

Explanation

Question 2 of 200

When sizing branch line, what is the maximum size a job fabricated welded fitting that can be used in a 6” NPS gas supply

Select one of the following:

Explanation

Question 3 of 200

Natural gas piping in industrial buildings shall be identified:

Select one of the following:

Explanation

Question 4 of 200

A panel-mounted ground fault circuit interrupting breaker protects all:

Select one of the following:

Explanation

Question 5 of 200

Branch circuit fuse size is determined by the:

Select one of the following:

Explanation

Question 6 of 200

The 24 volt control circuit supply for a residential gas furnace comes from a:

Select one of the following:

Explanation

Question 7 of 200

On an electrical schematic diagram, the safety controls are typically drawn:

Select one of the following:

Explanation

Question 8 of 200

The power supply to a residential gas furnace is:

Select one of the following:

Explanation

Question 9 of 200

As gauge number of a conductor increase, its current carrying capacity:

Select one of the following:

Explanation

Question 10 of 200

As more circuits are added to a panel, the total current drawn from the panel:

Select one of the following:

Explanation

Question 11 of 200

A hard, sharp pilot flame indicates

Select one of the following:

Explanation

Question 12 of 200

Direct current travels:

Select one of the following:

Explanation

Question 13 of 200

A receptacle-mounted ground fault interrupter protects against:

Select one of the following:

Explanation

Question 14 of 200

On an electrical schematic, the system is shown with the:

Select one of the following:

Explanation

Question 15 of 200

The normal fuse size for #12 AWG copper wire is:

Select one of the following:

Explanation

Question 16 of 200

A zero ohmmeter reading taken between the casing of a solenoid and a disconnected wire to the solenoid indicates that:

Select one of the following:

Explanation

Question 17 of 200

As the diameter of a conductor decreases, its resistance:

Select one of the following:

Explanation

Question 18 of 200

When can an on/off switch be installed in the neutral wire from an electrical panel to a gas furnace:

Select one of the following:

Explanation

Question 19 of 200

A thermostat with a single mercury bulb which controls a single stage heat, single stage cool unit is a ___________ control:

Select one of the following:

Explanation

Question 20 of 200

How tight should a thermocouple connection be:

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?