NATE Gas Heat Practice Guide Questions with Correct
Answers | Latest Update | Guaranteed Pass
What precautions are required when mounting any gas furnace on a wood platform in an attic?
- CORRECT ANSWER -None
The gas control valve may be damaged if exposed to an inlet pressure above what? - CORRECT
ANSWER -14 inch W.C.
How many elbows and joints should a vent connector have? - CORRECT ANSWER -As few as
possible to reduce resistance of flue gases.
Under what conditions, if any may the technician route the exhaust of the furnace into the
exhaust vent of the water heater: - CORRECT ANSWER -Under no conditions may you use the
water heater exhaust vent.
How may a technician terminate the intake and exhaust for proper operation of a high efficiency
gas furnace when using scheduled 40 PVC pipe: - CORRECT ANSWER -By using the specific
manufacturers termination kit or make one to meet their requirements.
When suspended with metal strap and no saddle, flexible duct should be: - CORRECT ANSWER -
supported with a minimum strap width of
1/2".
A technician is installing a gas furnace and the customer has decided not to install an air
conditioner. Making this decision, the affect it will have on the installation of the supply
ductwork is: - CORRECT ANSWER -Leave adequate space should be allowed for addition of a coil
in the future when feasible.
Leveling of a Mercury bulb is __________ - CORRECT ANSWER -Critical
,Spray-type atomizing humidifiers are installed to do what? - CORRECT ANSWER -Discharge
moisture into the supply duct.
Electronic air cleaners (EAC) installed in a gas furnace system should be wired so they: -
CORRECT ANSWER -Only operate any time the EAC On-Off switch is turned to ON.
The LP gas manifold pressure is commonly what? - CORRECT ANSWER -10 to 11 in. W.C.
The polarity of a 120V gas furnace equipped with electronic flame rectification is important
because: - CORRECT ANSWER -The ignition control may not prove flame.
Using a voltmeter, a technician can determine voltage drop at a gas furnace: - CORRECT
ANSWER -With the furnace not operating and then with the furnace operating.
The setting on a 4 speed PSC blower motor can be changed by changing the: - CORRECT
ANSWER -Motor tap connection.
When starting up a dual system, the temperature rise method for determining airflow cannot be
used with compressor cycle of the heat pump because: - CORRECT ANSWER -The capacity of the
system varies too much with outdoor temperature.
The flame pattern a technician would expect to see on a properly operating single stage gas
furnace equipped with "in shot" type burner is a: - CORRECT ANSWER -Hard and forceful flame
with a light blue appearance and little or no yellow.
What is recommended method for a pressurization leak test of a fuel gas pipe? - CORRECT
ANSWER -Compressed air
, What is a diaphragm type differential pressure gauge used for? - CORRECT ANSWER -Measure
air pressure.
The pressure reading on a manometer is expressed in: - CORRECT ANSWER -Inches of water.
A technician measures the return air temperature of a 100,000 BTU output gas furnace to be
65°F and the supply side air temperature is 135°F. Calculate the CFM. - CORRECT ANSWER -The
CFM would be 1323.
A dirty or clogged air filter in an operating gas furnace can cause what? - CORRECT ANSWER -
Increase temperature rise.
What can bent vanes on a direct drive blower wheel in a gas furnace cause? - CORRECT
ANSWER -Loss in airflow, excessive blower motor wear, and increase noise.
A gas clothes dryer can interfere with the operation of a nearby natural draft gas furnace with
an atmospheric burner by: - CORRECT ANSWER -Stealing combustion air preventing complete
fuel burning.
During a preventive maintenance check of a gas furnace, what should always be checked for on
the ductwork? - CORRECT ANSWER -Ductwork should always be checked for leaks and damage.
When performing a cycle check during a preventive maintenance call, the technician should: -
CORRECT ANSWER -~First check with the owner of the equipment for their opinion of
performance.
~The next step is to turn the unit off at the thermostat system switch. ~Next the technician
should set the FAN switch to ON and check that the blower is running.
What measurements are required to calculate the CFM of a gas furnace are? - CORRECT
ANSWER -~Entering air temperature
Answers | Latest Update | Guaranteed Pass
What precautions are required when mounting any gas furnace on a wood platform in an attic?
- CORRECT ANSWER -None
The gas control valve may be damaged if exposed to an inlet pressure above what? - CORRECT
ANSWER -14 inch W.C.
How many elbows and joints should a vent connector have? - CORRECT ANSWER -As few as
possible to reduce resistance of flue gases.
Under what conditions, if any may the technician route the exhaust of the furnace into the
exhaust vent of the water heater: - CORRECT ANSWER -Under no conditions may you use the
water heater exhaust vent.
How may a technician terminate the intake and exhaust for proper operation of a high efficiency
gas furnace when using scheduled 40 PVC pipe: - CORRECT ANSWER -By using the specific
manufacturers termination kit or make one to meet their requirements.
When suspended with metal strap and no saddle, flexible duct should be: - CORRECT ANSWER -
supported with a minimum strap width of
1/2".
A technician is installing a gas furnace and the customer has decided not to install an air
conditioner. Making this decision, the affect it will have on the installation of the supply
ductwork is: - CORRECT ANSWER -Leave adequate space should be allowed for addition of a coil
in the future when feasible.
Leveling of a Mercury bulb is __________ - CORRECT ANSWER -Critical
,Spray-type atomizing humidifiers are installed to do what? - CORRECT ANSWER -Discharge
moisture into the supply duct.
Electronic air cleaners (EAC) installed in a gas furnace system should be wired so they: -
CORRECT ANSWER -Only operate any time the EAC On-Off switch is turned to ON.
The LP gas manifold pressure is commonly what? - CORRECT ANSWER -10 to 11 in. W.C.
The polarity of a 120V gas furnace equipped with electronic flame rectification is important
because: - CORRECT ANSWER -The ignition control may not prove flame.
Using a voltmeter, a technician can determine voltage drop at a gas furnace: - CORRECT
ANSWER -With the furnace not operating and then with the furnace operating.
The setting on a 4 speed PSC blower motor can be changed by changing the: - CORRECT
ANSWER -Motor tap connection.
When starting up a dual system, the temperature rise method for determining airflow cannot be
used with compressor cycle of the heat pump because: - CORRECT ANSWER -The capacity of the
system varies too much with outdoor temperature.
The flame pattern a technician would expect to see on a properly operating single stage gas
furnace equipped with "in shot" type burner is a: - CORRECT ANSWER -Hard and forceful flame
with a light blue appearance and little or no yellow.
What is recommended method for a pressurization leak test of a fuel gas pipe? - CORRECT
ANSWER -Compressed air
, What is a diaphragm type differential pressure gauge used for? - CORRECT ANSWER -Measure
air pressure.
The pressure reading on a manometer is expressed in: - CORRECT ANSWER -Inches of water.
A technician measures the return air temperature of a 100,000 BTU output gas furnace to be
65°F and the supply side air temperature is 135°F. Calculate the CFM. - CORRECT ANSWER -The
CFM would be 1323.
A dirty or clogged air filter in an operating gas furnace can cause what? - CORRECT ANSWER -
Increase temperature rise.
What can bent vanes on a direct drive blower wheel in a gas furnace cause? - CORRECT
ANSWER -Loss in airflow, excessive blower motor wear, and increase noise.
A gas clothes dryer can interfere with the operation of a nearby natural draft gas furnace with
an atmospheric burner by: - CORRECT ANSWER -Stealing combustion air preventing complete
fuel burning.
During a preventive maintenance check of a gas furnace, what should always be checked for on
the ductwork? - CORRECT ANSWER -Ductwork should always be checked for leaks and damage.
When performing a cycle check during a preventive maintenance call, the technician should: -
CORRECT ANSWER -~First check with the owner of the equipment for their opinion of
performance.
~The next step is to turn the unit off at the thermostat system switch. ~Next the technician
should set the FAN switch to ON and check that the blower is running.
What measurements are required to calculate the CFM of a gas furnace are? - CORRECT
ANSWER -~Entering air temperature
