G2 PREP TEST FINAL STUDY PAPER 2026
COMPLETE QUESTIONS AND ANSWERS
◉ When can a natural draft decorative appliance be installed in a
bedroom:
A) Never
B) Always
C) Only when certified for installations in bedrooms
D) Only when under 50,000 Btuh input. Answer: C
◉ When a gas fired appliance is vented into a chimney flue serving
an appliance which burns solid fuel in a commercial or industrial
application, how shall the vent from the gas appliance be installed:
A) through a separate flue opening above the flue pipe connection
from the other appliance
B) through a separate flue opening below the flue pipe connector
from the other appliance
C) through a job fabricated branch fitting located not more than 30
inches (760mm)
D) through a field fabricated branch fitting located no more than 60
inches (1500mm) from the flue entrance to the chimney. Answer: A)
through a separate flue opening above the flue pipe connection from
the other appliance
,◉ A boiler room contains the following natural draft appliances: 2
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?
A) 100 square inches
B) 200 square inches
C) 900 square inches
D) 1800 square inches. Answer: B) 200 square inches
◉ When is it necessary to use a sleeve at the point the connector
enters the chimney when a vent connector is being used to connect
an appliance to a masonry chimney?
A) always
B) never
C) only when the vent connector is lager than 6 inches (150mm) in
diameter
D) only when the appliance is equipped with a draft hood. Answer:
A) always
◉ What happens when the humidstat for a power humidifier closes?
A) the humidifier solenoid valve opens
B) the humidifier motor starts to turn
C) the furnace fan starts , then the humidifier starts
,D) the gas valve opens, then the humidifier starts. Answer: A) the
humidifier solenoid valve opens
◉ What happens to the system in the heating mode if the pre-filter
in an electronic air cleaner gets plugged with dirt?
A) the fan motor cycles on overload
B) the burner shuts off on hi-limit
C) the house overheats
D) the heat anticipator burns out. Answer: B) the burner shuts off on
hi-limit
◉ How are electronic cleaners wired?
A) in parallel with the fan motor
B) in series with the fan motor
C) in parallel with the fan
D) in series with the fan. Answer: A) in parallel with the fan motor
◉ What are the main components of an electronic air cleaner?
A) Ionizing wires, high voltage transformer and collector plates
B) humidistat, ionizing wires and collector plates
C) thermostat, high voltage transformer and ionizing wires
D) ionizing wires, collector plates and fan control switch. Answer: A)
Ionizing wires, high voltage transformer and collector plates
, ◉ When a furnace mounted humidifier is used. shorter furnace
blower "on" cycles results in
A) inadequate humidity levels
B) ideal humidity levels
C) excessive humidity swings
D) uncontrolled humidity swings. Answer: A) inadequate humidity
levels
◉ When sizing a branch line, what is the minimum size of job
fabricated welded fitting that can be used on a NPS 6 gas supply
header?
A) 1/2" NPS
B) 3/4" NPS
C) 2" NPS
D3" NPS. Answer: B) 3/4" NPS
◉ Where shall a manual shut off valve be installed to control the
supply of gas to a commercial or industrial type of appliance?
a)In either the drop or riser as close as possible to the valve train.
b)Downstream of all controls on the valve train.
c)As close to the outlet of the gas meter as possible.
COMPLETE QUESTIONS AND ANSWERS
◉ When can a natural draft decorative appliance be installed in a
bedroom:
A) Never
B) Always
C) Only when certified for installations in bedrooms
D) Only when under 50,000 Btuh input. Answer: C
◉ When a gas fired appliance is vented into a chimney flue serving
an appliance which burns solid fuel in a commercial or industrial
application, how shall the vent from the gas appliance be installed:
A) through a separate flue opening above the flue pipe connection
from the other appliance
B) through a separate flue opening below the flue pipe connector
from the other appliance
C) through a job fabricated branch fitting located not more than 30
inches (760mm)
D) through a field fabricated branch fitting located no more than 60
inches (1500mm) from the flue entrance to the chimney. Answer: A)
through a separate flue opening above the flue pipe connection from
the other appliance
,◉ A boiler room contains the following natural draft appliances: 2
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?
A) 100 square inches
B) 200 square inches
C) 900 square inches
D) 1800 square inches. Answer: B) 200 square inches
◉ When is it necessary to use a sleeve at the point the connector
enters the chimney when a vent connector is being used to connect
an appliance to a masonry chimney?
A) always
B) never
C) only when the vent connector is lager than 6 inches (150mm) in
diameter
D) only when the appliance is equipped with a draft hood. Answer:
A) always
◉ What happens when the humidstat for a power humidifier closes?
A) the humidifier solenoid valve opens
B) the humidifier motor starts to turn
C) the furnace fan starts , then the humidifier starts
,D) the gas valve opens, then the humidifier starts. Answer: A) the
humidifier solenoid valve opens
◉ What happens to the system in the heating mode if the pre-filter
in an electronic air cleaner gets plugged with dirt?
A) the fan motor cycles on overload
B) the burner shuts off on hi-limit
C) the house overheats
D) the heat anticipator burns out. Answer: B) the burner shuts off on
hi-limit
◉ How are electronic cleaners wired?
A) in parallel with the fan motor
B) in series with the fan motor
C) in parallel with the fan
D) in series with the fan. Answer: A) in parallel with the fan motor
◉ What are the main components of an electronic air cleaner?
A) Ionizing wires, high voltage transformer and collector plates
B) humidistat, ionizing wires and collector plates
C) thermostat, high voltage transformer and ionizing wires
D) ionizing wires, collector plates and fan control switch. Answer: A)
Ionizing wires, high voltage transformer and collector plates
, ◉ When a furnace mounted humidifier is used. shorter furnace
blower "on" cycles results in
A) inadequate humidity levels
B) ideal humidity levels
C) excessive humidity swings
D) uncontrolled humidity swings. Answer: A) inadequate humidity
levels
◉ When sizing a branch line, what is the minimum size of job
fabricated welded fitting that can be used on a NPS 6 gas supply
header?
A) 1/2" NPS
B) 3/4" NPS
C) 2" NPS
D3" NPS. Answer: B) 3/4" NPS
◉ Where shall a manual shut off valve be installed to control the
supply of gas to a commercial or industrial type of appliance?
a)In either the drop or riser as close as possible to the valve train.
b)Downstream of all controls on the valve train.
c)As close to the outlet of the gas meter as possible.
