7/27/25, 11:20 AM G2 prep
G2 PREP EXAM 2025 LATEST VERSION WITH COMPLETE
QUESTIONS AND CORRECT DETAILED ANSWERS
\VERIFIED 100% ALREADY GRADED A+
Science Engineering Electrical Engineering
Terms in this set (567)
1. What is the most effective b
way to prevent lime
deposits in the water
heater?
a. Install a charcoal filter
upstream of the water
heater
b. Install a water softening
system
c. Install a cartridge filter
upstream of the water
heater
d. Install an aluminum anode
2. A gurgling sound due to d
firing a water heater may
be a symptom of:
a. Low gas pressure
b. Over firing
c. Too low water
temperature, erratic
temperature control
d. The need for de-liming
/ 1/177
,7/27/25, 11:20 AM G2 prep
3. A low limit is provided on d
a hot water tank which
provides both space
heating and
domestic hot water to
a. Prevent rusting in the system
b. Prevent freeze-up
c. Reduce oil consumption
d. Assure a constant supply
of domestic hot water
4. A customer complains that c
the hot water runs out in
the middle of one shower.
The water temperature
coming out of the tap is 140
ºF and begins falling within
1 minute.
After drawing water for 5
minutes, the water
temperature at the
bottom of the tank
is measured at 130ºF 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
/ 2/177
,7/27/25, 11:20 AM G2 prep
5. The most likely cause b
of a puddle of water at
the side of a water heater
where the
drain cock and relief valve
are located is that:
a. The drain cock is opening
intermittently
b. The relief valve is opening
periodically
c. It is caused by
condensation when cold
water enters the heater
d. The Unitrol fitting is leaking
and resealing itself
6. The high limit switch on a d
water heater
a. Sets the temperature of the
outlet water
b. Sets the temperature for
the storage tank heater
c. Limits the temperature
of the water entering
the heater
d. Limits the temperature in the
heater
7. Scenario: There is a d
storage type of system.
The boiler is hot, the
circulating pump
motor is running, the
thermostat is calling for
heat and the upstairs is
cold. The most likely
problem is:
a. A faulty limit control
b. A faulty operator
c. An open relief valve
d. A broken pump coupling
/ 3/177
, 7/27/25, 11:20 AM G2 prep
8. What action should be b
taken when testing the
control system on a
water heater
which is not working, and
the following results are
obtained?
Open circuit test—27
millivolts Closed circuit
test—13 millivolts Drop
out test—10 millivolts
a. Replace the thermocouple
b. Replace the control valve
c. Replace the pilot
d. Replace the high limit control
9. If a water heater has black d
scorch marks on the front
above the burner access
opening, what should be
done?
a. Decrease the amount of
primary air and decrease
the manifold pressure
b. Adjust the pilot flame and
increase the manifold
pressure
c. Adjust the burner flame
and decrease the draft
d. Adjust the burner flame
and check the flue baffle
for soot or scale
/ 4/177
G2 PREP EXAM 2025 LATEST VERSION WITH COMPLETE
QUESTIONS AND CORRECT DETAILED ANSWERS
\VERIFIED 100% ALREADY GRADED A+
Science Engineering Electrical Engineering
Terms in this set (567)
1. What is the most effective b
way to prevent lime
deposits in the water
heater?
a. Install a charcoal filter
upstream of the water
heater
b. Install a water softening
system
c. Install a cartridge filter
upstream of the water
heater
d. Install an aluminum anode
2. A gurgling sound due to d
firing a water heater may
be a symptom of:
a. Low gas pressure
b. Over firing
c. Too low water
temperature, erratic
temperature control
d. The need for de-liming
/ 1/177
,7/27/25, 11:20 AM G2 prep
3. A low limit is provided on d
a hot water tank which
provides both space
heating and
domestic hot water to
a. Prevent rusting in the system
b. Prevent freeze-up
c. Reduce oil consumption
d. Assure a constant supply
of domestic hot water
4. A customer complains that c
the hot water runs out in
the middle of one shower.
The water temperature
coming out of the tap is 140
ºF and begins falling within
1 minute.
After drawing water for 5
minutes, the water
temperature at the
bottom of the tank
is measured at 130ºF 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
/ 2/177
,7/27/25, 11:20 AM G2 prep
5. The most likely cause b
of a puddle of water at
the side of a water heater
where the
drain cock and relief valve
are located is that:
a. The drain cock is opening
intermittently
b. The relief valve is opening
periodically
c. It is caused by
condensation when cold
water enters the heater
d. The Unitrol fitting is leaking
and resealing itself
6. The high limit switch on a d
water heater
a. Sets the temperature of the
outlet water
b. Sets the temperature for
the storage tank heater
c. Limits the temperature
of the water entering
the heater
d. Limits the temperature in the
heater
7. Scenario: There is a d
storage type of system.
The boiler is hot, the
circulating pump
motor is running, the
thermostat is calling for
heat and the upstairs is
cold. The most likely
problem is:
a. A faulty limit control
b. A faulty operator
c. An open relief valve
d. A broken pump coupling
/ 3/177
, 7/27/25, 11:20 AM G2 prep
8. What action should be b
taken when testing the
control system on a
water heater
which is not working, and
the following results are
obtained?
Open circuit test—27
millivolts Closed circuit
test—13 millivolts Drop
out test—10 millivolts
a. Replace the thermocouple
b. Replace the control valve
c. Replace the pilot
d. Replace the high limit control
9. If a water heater has black d
scorch marks on the front
above the burner access
opening, what should be
done?
a. Decrease the amount of
primary air and decrease
the manifold pressure
b. Adjust the pilot flame and
increase the manifold
pressure
c. Adjust the burner flame
and decrease the draft
d. Adjust the burner flame
and check the flue baffle
for soot or scale
/ 4/177
