NATE Gas QUESTIONS AND ANSWERS 100% ACCURATE.
A thermopile system usually generates its own control circuit voltage of - 750 mV
There are two generally used methods for controlling temperature and humidity within individual
zones of a residence. One is to use dampers to control supply airflow to each zone. What is the
other method? - Use separate and independent systems to condition the air in each zone
The complaint is that there is static electricity throughout the house. The home has a bypass
humidifier. The technician has checked the humidistat and verified that it is set properly.
What would the technician check next? - Check that the humidifier damper is open
A line voltage fuse is sized to - protect from excessive voltage
14. With a non-direct vented furnace located in a basement, what are the requirements for the
space to qualify as an "unconfined space"? - At least 50 ft of air volume for every
1000 Btu/h capacity of ail combustion appliances in the space
When troubleshooting a blower motor cir on a packaged system, 244V is measured across the
motor and no amperage is measured. What is a likely problem with this system? - An internal
overload device is open
If too much primary air is used on a ribbon burner, the flame will - lift off the burner
What is an industry accepted method for locating a suspected natural gas leak? - a soap solution
The first check made for most electrical troubleshooting is a - voltage check of the supply line
Which ACCA manual should the technician consult to make accurate residential load
calculations? - Manual J
Drive cleats are typically installed where on rectangular duct? - on the shorter sides
What is a likely problem if a gas furnace has a temperature differential across the heat exchanger
which exceeds the value on the manufacturer's rating plate? - Inadequate system airflow
A typical four-way multipositional gas furnace is converted from upflow to downflow by -
turning the furnace upside down with specified alterations
What is the relationship between inrush current and holding current of the relay coil? - Inrush
current is always greater than holding current
A furnace using an integrated control board is blowing cold air at the end of the cycle. What is
the likely problem with this system? - The blower off delay is set too long
, The outdoor winter temperature for which a gas furnace is to be sized is called the out design
temperature. The tables for winter outdoor design temperatures are measured by - dry bulb
temperature only
Before starting a gas furnace after its installation, the technician should do a visual check of all
wiring on the equipment. What must be included with these checks? - A check that all
connections are secure and tight
How long should a gas furnace operate before a combustion test is taken? - After the gas furnace
has reached steady state
Aluminized steel heat exchangers are coated to prevent - rusting of the heat exchanger
Bent hands on a direct drive blower wheel in a gas furnace can cause - cutout on high limit,
excessive blower moto wear, and reduced motor torque
A dirty or clogged air filter in an operating heat pump system can cause - an increased
temperature rise
Condensing furnaces take advantage of what additional form of heat contained in the flue gases?
- latent heat
How should a technician evaluate the circuitry on a residential gas furnace when the wiring
diagram is missing? - Draw the circuits on a notepad
You are responding to a report of "drafty air" in a room during the heating season.
The following conditions exist:
*Discharge air velocity 815 fpm,
*Supply temperature 110°F,
#Airflow volume 150 CFM
What is the problem? - Register velocity is too low
How may a technician terminate the intake and exhaust for proper operation of a condensing gas
furnace when using PVC schedule 40 pipe? - Use the specific manufacturer's termination kit or
make one to meet their requirements
A flame on a high efficiency gas furnace is burning primarily yellow. What, if anythi is the
problem in this furnace? - The flame is burning without sufficient combustion air
What is the minimum acceptable reading for a flame sensor? - 1 microamp
Electronic air cleaners for gas furnaces are sized based on - The CFM of the return side of the
heating system.
A thermopile system usually generates its own control circuit voltage of - 750 mV
There are two generally used methods for controlling temperature and humidity within individual
zones of a residence. One is to use dampers to control supply airflow to each zone. What is the
other method? - Use separate and independent systems to condition the air in each zone
The complaint is that there is static electricity throughout the house. The home has a bypass
humidifier. The technician has checked the humidistat and verified that it is set properly.
What would the technician check next? - Check that the humidifier damper is open
A line voltage fuse is sized to - protect from excessive voltage
14. With a non-direct vented furnace located in a basement, what are the requirements for the
space to qualify as an "unconfined space"? - At least 50 ft of air volume for every
1000 Btu/h capacity of ail combustion appliances in the space
When troubleshooting a blower motor cir on a packaged system, 244V is measured across the
motor and no amperage is measured. What is a likely problem with this system? - An internal
overload device is open
If too much primary air is used on a ribbon burner, the flame will - lift off the burner
What is an industry accepted method for locating a suspected natural gas leak? - a soap solution
The first check made for most electrical troubleshooting is a - voltage check of the supply line
Which ACCA manual should the technician consult to make accurate residential load
calculations? - Manual J
Drive cleats are typically installed where on rectangular duct? - on the shorter sides
What is a likely problem if a gas furnace has a temperature differential across the heat exchanger
which exceeds the value on the manufacturer's rating plate? - Inadequate system airflow
A typical four-way multipositional gas furnace is converted from upflow to downflow by -
turning the furnace upside down with specified alterations
What is the relationship between inrush current and holding current of the relay coil? - Inrush
current is always greater than holding current
A furnace using an integrated control board is blowing cold air at the end of the cycle. What is
the likely problem with this system? - The blower off delay is set too long
, The outdoor winter temperature for which a gas furnace is to be sized is called the out design
temperature. The tables for winter outdoor design temperatures are measured by - dry bulb
temperature only
Before starting a gas furnace after its installation, the technician should do a visual check of all
wiring on the equipment. What must be included with these checks? - A check that all
connections are secure and tight
How long should a gas furnace operate before a combustion test is taken? - After the gas furnace
has reached steady state
Aluminized steel heat exchangers are coated to prevent - rusting of the heat exchanger
Bent hands on a direct drive blower wheel in a gas furnace can cause - cutout on high limit,
excessive blower moto wear, and reduced motor torque
A dirty or clogged air filter in an operating heat pump system can cause - an increased
temperature rise
Condensing furnaces take advantage of what additional form of heat contained in the flue gases?
- latent heat
How should a technician evaluate the circuitry on a residential gas furnace when the wiring
diagram is missing? - Draw the circuits on a notepad
You are responding to a report of "drafty air" in a room during the heating season.
The following conditions exist:
*Discharge air velocity 815 fpm,
*Supply temperature 110°F,
#Airflow volume 150 CFM
What is the problem? - Register velocity is too low
How may a technician terminate the intake and exhaust for proper operation of a condensing gas
furnace when using PVC schedule 40 pipe? - Use the specific manufacturer's termination kit or
make one to meet their requirements
A flame on a high efficiency gas furnace is burning primarily yellow. What, if anythi is the
problem in this furnace? - The flame is burning without sufficient combustion air
What is the minimum acceptable reading for a flame sensor? - 1 microamp
Electronic air cleaners for gas furnaces are sized based on - The CFM of the return side of the
heating system.
