G2 Gas Technician Module 18 Revised,
G2 Gas Technician Module 24 Revised,
G2 Gas Technician Module 23 Revised,
G2 Gas Technician Module 22 Revised,
G2 Gas Technician Module 21 Revised,
G2 Gas Technician Module 20 Revised,
G2 Gas Technician Module 19 CORRECT
100%
What is a temperature control made of in a water heater? Which one is the sensing
element? - ANSWER Rod and tube. Rod is steel and tube is copper. Copper is the
sensing element.
Temperature settings on a water heater? - ANSWER Hot - 160 F
Normal - 130 F
Warm - 120 F
What does a unitrol have in it? - ANSWER Temperature and pressure relief valve,
E.C.O., Main Gas valves, Pilot Gas Valve and a gas regulator
What temp does a temperature and pressure relief valve fusible link melt at? Pressure
relieve at? - ANSWER Melts at 210 F and relieves itself at 150 psi
How does a dip tube function? - ANSWER Allows cold water to enter near the bottom of
the tank as hot water exits the top
What do anodes do in a water heater? When do you need to change them? - ANSWER
Prevents the interior of the tank from corroding and should be changed when its
diameter is 3/8"
What are the components of an instantaneous water heater? - ANSWER Pump, pump
control, flow switch, temperature and pressure relief valve, and a limit control
What must be done with a Twinned Water heater system to ensure it runs properly? -
ANSWER Inlet and outlet piping must have equal resistance on each tank.
What clearance must a direct vent water heater have on the burner side? - ANSWER 3
feet
,What metals are not acceptable in potable water applications? - ANSWER Ferrous
metals
What is the maximum allowable length of supply and return piping in a combination
water heating system? - ANSWER Max supply and return piping is 50 feet
Can you use chemicals in a combination system? - ANSWER No
How do you size the pumps in a combination system? - ANSWER To match the flow
requirements of the heating system
What is the minimum size and type of water heater that is recommended for a
combination system? - ANSWER 40 gallon high-recovery or high efficiency gas-fired
water heater
What temperature difference do you want from inlet to outlet on a combination system?
- ANSWER 20 F
How do you size a circulating pump? - ANSWER 1 gpm for each 10000 btuh and friction
loss is 1 foot for each 40 feet of pipe
What controls the water temp and gas pressure on a direct fired storage heater? -
ANSWER Unitrol
What are the components of a direct fired storage heater(under fired storage heater) -
ANSWER Dip tube, anode, temperature and pressure relief valve, and mixing valve
What are the components of a hi-efficiency water heater? - ANSWER E.C.O.,
temperature and pressure relief valve, anode and dip tube
What are the normal operating temps of a unitrol - ANSWER 130 F
What does an E.C.O. do? - ANSWER Shuts off gas valve in a high temperature
situation
How is temp rise determined on an under fired storage heater? - ANSWER Inlet
compared to outlet
How can you tell a water heater has a build up of lime? - ANSWER Sounds like it is
percolating.
How do you delime a water heater? How do you prevent it from starting? - ANSWER
Delime with a vinegar or a chemical solution(environmentally friendly) and prevent it
with a water softener
, What type of solder do you use when soldering water lines? - ANSWER Lead free
What is the purpose of a mixing valve and what is the temperature setting? - ANSWER
Controls water temperature and sets it at 120 F
How is legionnaires disease created? - ANSWER Temperatures lower then 105 F in
ponding water.
What acts as a heat exchanger in an underfired storage water heater? - ANSWER The
flue(baffle)
What improves heat transfer in a residential water heater? - ANSWER Having the baffle
spiral
What does an expansion tank do? - ANSWER To allow room for heated water to
expand so it doesn't burst pipes
Where are isolation valves installed on a combination system? - ANSWER At each unit
and wherever necessary
What are two reason check valves are used in a combination system? - ANSWER To
stop return water from cooling the supply water and to prevent cold water from entering
the rad
Can you use chemicals in a combination system? - ANSWER No
What is the purpose of a pressure reducing valve? - ANSWER To reduce pressure from
street to system pressure (12 psi)
What is the purpose of a circulating pump? - ANSWER To keep fluid circulating the
pumping system
List two sources of regulations and standards of practice that influence decisions
concerning air flow in residential construction. - ANSWER F280 and F326
Name three methods of heat transfer. - ANSWER Conduction, Convection and Radiant
What is enthalpy? - ANSWER All of sensible heat, latent heat contained in a substance
when heat is being transfer
Why is air movement an important consideration for building comfort? - ANSWER Air
movement decrease or increase the rate of heating gain or loss from building and
human bodies
Can Gas Technicians conduct heat loss calculations True or False? - ANSWER True if
trained
G2 Gas Technician Module 24 Revised,
G2 Gas Technician Module 23 Revised,
G2 Gas Technician Module 22 Revised,
G2 Gas Technician Module 21 Revised,
G2 Gas Technician Module 20 Revised,
G2 Gas Technician Module 19 CORRECT
100%
What is a temperature control made of in a water heater? Which one is the sensing
element? - ANSWER Rod and tube. Rod is steel and tube is copper. Copper is the
sensing element.
Temperature settings on a water heater? - ANSWER Hot - 160 F
Normal - 130 F
Warm - 120 F
What does a unitrol have in it? - ANSWER Temperature and pressure relief valve,
E.C.O., Main Gas valves, Pilot Gas Valve and a gas regulator
What temp does a temperature and pressure relief valve fusible link melt at? Pressure
relieve at? - ANSWER Melts at 210 F and relieves itself at 150 psi
How does a dip tube function? - ANSWER Allows cold water to enter near the bottom of
the tank as hot water exits the top
What do anodes do in a water heater? When do you need to change them? - ANSWER
Prevents the interior of the tank from corroding and should be changed when its
diameter is 3/8"
What are the components of an instantaneous water heater? - ANSWER Pump, pump
control, flow switch, temperature and pressure relief valve, and a limit control
What must be done with a Twinned Water heater system to ensure it runs properly? -
ANSWER Inlet and outlet piping must have equal resistance on each tank.
What clearance must a direct vent water heater have on the burner side? - ANSWER 3
feet
,What metals are not acceptable in potable water applications? - ANSWER Ferrous
metals
What is the maximum allowable length of supply and return piping in a combination
water heating system? - ANSWER Max supply and return piping is 50 feet
Can you use chemicals in a combination system? - ANSWER No
How do you size the pumps in a combination system? - ANSWER To match the flow
requirements of the heating system
What is the minimum size and type of water heater that is recommended for a
combination system? - ANSWER 40 gallon high-recovery or high efficiency gas-fired
water heater
What temperature difference do you want from inlet to outlet on a combination system?
- ANSWER 20 F
How do you size a circulating pump? - ANSWER 1 gpm for each 10000 btuh and friction
loss is 1 foot for each 40 feet of pipe
What controls the water temp and gas pressure on a direct fired storage heater? -
ANSWER Unitrol
What are the components of a direct fired storage heater(under fired storage heater) -
ANSWER Dip tube, anode, temperature and pressure relief valve, and mixing valve
What are the components of a hi-efficiency water heater? - ANSWER E.C.O.,
temperature and pressure relief valve, anode and dip tube
What are the normal operating temps of a unitrol - ANSWER 130 F
What does an E.C.O. do? - ANSWER Shuts off gas valve in a high temperature
situation
How is temp rise determined on an under fired storage heater? - ANSWER Inlet
compared to outlet
How can you tell a water heater has a build up of lime? - ANSWER Sounds like it is
percolating.
How do you delime a water heater? How do you prevent it from starting? - ANSWER
Delime with a vinegar or a chemical solution(environmentally friendly) and prevent it
with a water softener
, What type of solder do you use when soldering water lines? - ANSWER Lead free
What is the purpose of a mixing valve and what is the temperature setting? - ANSWER
Controls water temperature and sets it at 120 F
How is legionnaires disease created? - ANSWER Temperatures lower then 105 F in
ponding water.
What acts as a heat exchanger in an underfired storage water heater? - ANSWER The
flue(baffle)
What improves heat transfer in a residential water heater? - ANSWER Having the baffle
spiral
What does an expansion tank do? - ANSWER To allow room for heated water to
expand so it doesn't burst pipes
Where are isolation valves installed on a combination system? - ANSWER At each unit
and wherever necessary
What are two reason check valves are used in a combination system? - ANSWER To
stop return water from cooling the supply water and to prevent cold water from entering
the rad
Can you use chemicals in a combination system? - ANSWER No
What is the purpose of a pressure reducing valve? - ANSWER To reduce pressure from
street to system pressure (12 psi)
What is the purpose of a circulating pump? - ANSWER To keep fluid circulating the
pumping system
List two sources of regulations and standards of practice that influence decisions
concerning air flow in residential construction. - ANSWER F280 and F326
Name three methods of heat transfer. - ANSWER Conduction, Convection and Radiant
What is enthalpy? - ANSWER All of sensible heat, latent heat contained in a substance
when heat is being transfer
Why is air movement an important consideration for building comfort? - ANSWER Air
movement decrease or increase the rate of heating gain or loss from building and
human bodies
Can Gas Technicians conduct heat loss calculations True or False? - ANSWER True if
trained
