NATE Gas & Heat Questions and Answers 2026/2027 – Verified Edition, A+
Grade|NATE Gas Heating Exam Prep – Verified Edition
What precautions are required when mounting any gas furnace on a wood platform in an attic? -
(answer)None
The gas control valve may be damaged if exposed to an inlet pressure above: - (answer)14 in. W.C.
How many elbows and joints should a vent connector have: - (answer)As few as possible to reduce
resistance of flue gases
What conditions, if any may a technician route the exhaust of the furnace into the exhaust vent of the
water heater? - (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: - (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: - (answer)Supported with a
minimum strap width of 1/2"
Installing a gas furnace and not an air conditioner has what affect on the installation of the supply
ductwork: - (answer)Leave adequate space should be allowed for addition of a coil in the future when
feasible
Leveling of a Mercury bulb is: - (answer)Critical
Spray-type atomizing humidifiers are installed to: - (answer)Discharge moisture into the supply duct
Electronic air cleaners (EAC) installed in a gas furnace system should be wired so they: - (answer)Only
operate any time the EAC On-Off switch is turned to ON.
The LP gas manifold pressure is commonly: - (answer)10 to 11 in. W.C.
, NATE Gas & Heat Questions and Answers 2026/2027 – Verified Edition, A+
Grade|NATE Gas Heating Exam Prep – Verified Edition
The polarity of a 120V gas furnace equipped with electronic flame rectification is important because: -
(answer)The ignition control may not prove flame
Using a voltmeter, a technician can determine voltage drop at a gas furnace: - (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: - (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: - (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: - (answer)Hard and forceful flame with a light blue appearance
and little to no yellow
Compressed air is recommended for a: - (answer)Pressurization leak test of fuel gas pipe
Diaphragm type differential pressure gauge is used to: - (answer)Measure air pressure
The pressure reading on a manometer is expressed in: - (answer)Inches of water
A technician measures the return air temperature of a 100,000 BTU output gas furnace to be 65 degrees
and the supply side air temperature is 135 degrees: - (answer)The CFM would be 1323
A dirty or clogged air filter in an operating gas furnace can cause an: - (answer)Increase temperature rise
Grade|NATE Gas Heating Exam Prep – Verified Edition
What precautions are required when mounting any gas furnace on a wood platform in an attic? -
(answer)None
The gas control valve may be damaged if exposed to an inlet pressure above: - (answer)14 in. W.C.
How many elbows and joints should a vent connector have: - (answer)As few as possible to reduce
resistance of flue gases
What conditions, if any may a technician route the exhaust of the furnace into the exhaust vent of the
water heater? - (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: - (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: - (answer)Supported with a
minimum strap width of 1/2"
Installing a gas furnace and not an air conditioner has what affect on the installation of the supply
ductwork: - (answer)Leave adequate space should be allowed for addition of a coil in the future when
feasible
Leveling of a Mercury bulb is: - (answer)Critical
Spray-type atomizing humidifiers are installed to: - (answer)Discharge moisture into the supply duct
Electronic air cleaners (EAC) installed in a gas furnace system should be wired so they: - (answer)Only
operate any time the EAC On-Off switch is turned to ON.
The LP gas manifold pressure is commonly: - (answer)10 to 11 in. W.C.
, NATE Gas & Heat Questions and Answers 2026/2027 – Verified Edition, A+
Grade|NATE Gas Heating Exam Prep – Verified Edition
The polarity of a 120V gas furnace equipped with electronic flame rectification is important because: -
(answer)The ignition control may not prove flame
Using a voltmeter, a technician can determine voltage drop at a gas furnace: - (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: - (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: - (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: - (answer)Hard and forceful flame with a light blue appearance
and little to no yellow
Compressed air is recommended for a: - (answer)Pressurization leak test of fuel gas pipe
Diaphragm type differential pressure gauge is used to: - (answer)Measure air pressure
The pressure reading on a manometer is expressed in: - (answer)Inches of water
A technician measures the return air temperature of a 100,000 BTU output gas furnace to be 65 degrees
and the supply side air temperature is 135 degrees: - (answer)The CFM would be 1323
A dirty or clogged air filter in an operating gas furnace can cause an: - (answer)Increase temperature rise
