GAS FITTER 2 NEWEST 2025-2026 EXAM
QUESTIONS AND DETAILED CORRECT
ANSWERS | A+ GRADE VERIFIED
ANSWERS
A customer complains that the hot water runs out in the
middle of one shower. The water temperature coming out
of the tap is 140 degrees and begins falling within one
minute. After drawing water for 5 minutes the water
temperature at the bottom of the tank is measured at 130
degrees and the burner has not come on. What is the
most likely cause?
A. The temperature control is out of calibration
B. The shower head passes too much water
C. the dip tube is cracked or broken
D. The temperature sensor is in the wrong location Correct
Answer A
As the outlet temperature decreases from a water heater
to the heating loop in a combination system the:
A. Heating output from the air handler decreases
B. Heating output from the air handler increases
C. Rate of heat transfer from the water to air increases
D. Greater the temperature drop through the heating loop
Correct Answer A
On a hydronic heater system what control responds to a
load change?
A. Low water cut off
,B. Expansion tank
C. Flow switch
D. Aquastat Correct Answer C
Which of the hydronic controls listed below de-energizes
the main burner if the operating control fails in the closed
position?
A. Low limit control
B. Temperature and pressure relief valve
C. High limit control
D. Flow switch Correct Answer C
The purpose of mixing valve on a combination system
employing a water heater to provide water for potable use
and provide space heating is to
A. Mix hot water with cold water in the heating loop
B. Mix cold water with the hot water supply to the domestic
plumbing system to maintain a consistent temperature of
domestic hot water
C. Mix cold water with the hot water supply to the heating
loop to maintain a consistent temperature of water in the
heating loop
D. Return some of the hot water to the tank so that it does
not run out of water Correct Answer C
A customer complains that the pilot goes out every once in
a while. This is the second service call for this problem this
month. When the pilot is re-established, the closed circuit
millivolt test stays steady at 14 millivolts. The magnet
drops out at 4 millivolts. What should be done next?
A. Replace the gas valve because the magnet is weak
,B. Clean and adjust the pilot and burners
C. Replace the thermocouple
D. Check for another problem such as down draft or pilot
position Correct Answer D
Combination systems are sized to deliver __________ of
the calculated heat loss of the building.
A. 90%
B. 95% to 105%
C. 120%
D. 200% Correct Answer C
The most likely cause of an intermittent hissing sound "like
water dripping on something hot" coming from a water
heater is:
A. an intermittent leak in the flue that seals once the tank
heats up
B. Condensation in the flue passage caused by drawing
water from the tank when the hot water has been depleted
C. Condensation in the flue passage caused by high
humidity in the combustion air supply to the water heater
D. Condensation in the flue passage caused by high
moisture content in the as supply Correct Answer B
Why is there a low limit on a hot water tank which supplies
both space heating and domestic hot water?
A. To prevent rusting in the system
B. To prevent freeze up
C. To reduce oil consumption
D. To assure a constant supply of domestic hot water
Correct Answer D
, Is leaded solder allowed on the heating potion of a
combination domestic heating/ hot water system?
A. Yes
B. No Correct Answer Yes
A forced draft burner has a blower that produces sufficient
pressure to overcome the resistance of the:
A. burner
B. burner and the appliance
C. burner and the appliance downdraft
D. venting system Correct Answer B
What materials are approved for joining single wall vent
connectors?
A. Duct tape
B. Pop rivets
C. Sheet metal screws
D. Silicone or adhesive Correct Answer C
How many Btu's are in a US gallon of oil?
A. 100,000
B. 120,000
C. 140,000
D. 175,000 Correct Answer C
A fan assist burner is?
A. Designed for better combustion
B. Designed for conversion boiler
C. Designed to overcome appliance friction
QUESTIONS AND DETAILED CORRECT
ANSWERS | A+ GRADE VERIFIED
ANSWERS
A customer complains that the hot water runs out in the
middle of one shower. The water temperature coming out
of the tap is 140 degrees and begins falling within one
minute. After drawing water for 5 minutes the water
temperature at the bottom of the tank is measured at 130
degrees and the burner has not come on. What is the
most likely cause?
A. The temperature control is out of calibration
B. The shower head passes too much water
C. the dip tube is cracked or broken
D. The temperature sensor is in the wrong location Correct
Answer A
As the outlet temperature decreases from a water heater
to the heating loop in a combination system the:
A. Heating output from the air handler decreases
B. Heating output from the air handler increases
C. Rate of heat transfer from the water to air increases
D. Greater the temperature drop through the heating loop
Correct Answer A
On a hydronic heater system what control responds to a
load change?
A. Low water cut off
,B. Expansion tank
C. Flow switch
D. Aquastat Correct Answer C
Which of the hydronic controls listed below de-energizes
the main burner if the operating control fails in the closed
position?
A. Low limit control
B. Temperature and pressure relief valve
C. High limit control
D. Flow switch Correct Answer C
The purpose of mixing valve on a combination system
employing a water heater to provide water for potable use
and provide space heating is to
A. Mix hot water with cold water in the heating loop
B. Mix cold water with the hot water supply to the domestic
plumbing system to maintain a consistent temperature of
domestic hot water
C. Mix cold water with the hot water supply to the heating
loop to maintain a consistent temperature of water in the
heating loop
D. Return some of the hot water to the tank so that it does
not run out of water Correct Answer C
A customer complains that the pilot goes out every once in
a while. This is the second service call for this problem this
month. When the pilot is re-established, the closed circuit
millivolt test stays steady at 14 millivolts. The magnet
drops out at 4 millivolts. What should be done next?
A. Replace the gas valve because the magnet is weak
,B. Clean and adjust the pilot and burners
C. Replace the thermocouple
D. Check for another problem such as down draft or pilot
position Correct Answer D
Combination systems are sized to deliver __________ of
the calculated heat loss of the building.
A. 90%
B. 95% to 105%
C. 120%
D. 200% Correct Answer C
The most likely cause of an intermittent hissing sound "like
water dripping on something hot" coming from a water
heater is:
A. an intermittent leak in the flue that seals once the tank
heats up
B. Condensation in the flue passage caused by drawing
water from the tank when the hot water has been depleted
C. Condensation in the flue passage caused by high
humidity in the combustion air supply to the water heater
D. Condensation in the flue passage caused by high
moisture content in the as supply Correct Answer B
Why is there a low limit on a hot water tank which supplies
both space heating and domestic hot water?
A. To prevent rusting in the system
B. To prevent freeze up
C. To reduce oil consumption
D. To assure a constant supply of domestic hot water
Correct Answer D
, Is leaded solder allowed on the heating potion of a
combination domestic heating/ hot water system?
A. Yes
B. No Correct Answer Yes
A forced draft burner has a blower that produces sufficient
pressure to overcome the resistance of the:
A. burner
B. burner and the appliance
C. burner and the appliance downdraft
D. venting system Correct Answer B
What materials are approved for joining single wall vent
connectors?
A. Duct tape
B. Pop rivets
C. Sheet metal screws
D. Silicone or adhesive Correct Answer C
How many Btu's are in a US gallon of oil?
A. 100,000
B. 120,000
C. 140,000
D. 175,000 Correct Answer C
A fan assist burner is?
A. Designed for better combustion
B. Designed for conversion boiler
C. Designed to overcome appliance friction
