G2 Gas Technician Module 19 Revised
If the venting on a high efficiency furnace runs through unheated spaces, what must be
done? - ANS-Insulate piping to prevent Condensation and freezing
What is condensate drain piping used for? - ANS-Dispose Liquid waste
Once the furnace is installed, what are the gas technician's responsibilities to the user?
- ANS-To instruct the the user in the safe and correct operation of all appliances and
equipment - clause 4.3.2
Which furnace type is the most popular? - ANS-High boy Up Flow
What type of furnace is used in areas of limited head room? - ANS-Horizontal Forced
Air
What is the AFUE rating of a typical medium efficiency furnace? - ANS-78% - 82%
Which category of furnace is standard atmospheric appliance? - ANS-Category 1
Is a fan necessary to move the flue gases through a gravity vent? Why? - ANS-No, hot
air rises.
Are high-efficiency furnaces power vented? - ANS-Yes
Which Vent is the most heat resistant? - ANS-Type A
On a forced draft burner, where is the fan located? - ANS-Upstream from the
combustion chamber.
What is the disadvantage of oversizing a furnace? - ANS-Inefficiency
How is the delivered air volume adjusted if a belt-drive fan motor is being used? -
ANS-Adjusting the pulleys of the motor
Must all defective heat exchangers be replaced immediately? - ANS-Yes
A high efficiency furnace incorporates how many heat exchangers? - ANS-Two
, On a furnace with no filter rack, what should be done? - ANS-Rack should be built on
return duct connection
What is a plenum? - ANS-Duct work system connected directly to the furnace
What should be done if a customer shows signs of Co poisoning? - ANS-Evacuate,
Shut off appliance, Call TSSA
Once a fan motor has been cleaned what are the next two steps? - ANS-Check
electrical wire for tighteness and clean the blower components
How is temperature rise determined? - ANS-Placing thermometer in the return and
supply plenums while the furnace is running
What tool should be used to clean the outside of the heat exchanger? - ANS-Soft Brush
How many heat exchangers do Natural Draft Furnace have? - ANS-One
How is Delta Temperature measured? and what should it match? - ANS-Supply Air
minus Return Air, It must not be less or more than Manufacturers Rating Plate
In a high efficiency furnace, which heat exchanger does the Supply air pass through
first? - ANS-The Secondary
What proves that your Induce blower is functional? - ANS-The pressure switch
How is Hot Surface Igniter diagnosed? - ANS-Connect leads to both wires, check for
voltage and Resistance
How is a belt motor in a furnace maintained? - ANS-Must be Oiled and Alignment
Where is the Automatic Damper located? - ANS-Down stream of the draft hood
What purpose does a Automatic damper serve? How does it work? - ANS-Reduce heat
loss up the chimney and it opens when burners fire and closes during the off cycle
What is Static Pressure in a furnace?, how is it measured?, and what standard must it
meet? - ANS-The pressure in the furnace at 90 degrees. It's measured with a
manometer It must meet Manufacturers Rating plate standard
If the venting on a high efficiency furnace runs through unheated spaces, what must be
done? - ANS-Insulate piping to prevent Condensation and freezing
What is condensate drain piping used for? - ANS-Dispose Liquid waste
Once the furnace is installed, what are the gas technician's responsibilities to the user?
- ANS-To instruct the the user in the safe and correct operation of all appliances and
equipment - clause 4.3.2
Which furnace type is the most popular? - ANS-High boy Up Flow
What type of furnace is used in areas of limited head room? - ANS-Horizontal Forced
Air
What is the AFUE rating of a typical medium efficiency furnace? - ANS-78% - 82%
Which category of furnace is standard atmospheric appliance? - ANS-Category 1
Is a fan necessary to move the flue gases through a gravity vent? Why? - ANS-No, hot
air rises.
Are high-efficiency furnaces power vented? - ANS-Yes
Which Vent is the most heat resistant? - ANS-Type A
On a forced draft burner, where is the fan located? - ANS-Upstream from the
combustion chamber.
What is the disadvantage of oversizing a furnace? - ANS-Inefficiency
How is the delivered air volume adjusted if a belt-drive fan motor is being used? -
ANS-Adjusting the pulleys of the motor
Must all defective heat exchangers be replaced immediately? - ANS-Yes
A high efficiency furnace incorporates how many heat exchangers? - ANS-Two
, On a furnace with no filter rack, what should be done? - ANS-Rack should be built on
return duct connection
What is a plenum? - ANS-Duct work system connected directly to the furnace
What should be done if a customer shows signs of Co poisoning? - ANS-Evacuate,
Shut off appliance, Call TSSA
Once a fan motor has been cleaned what are the next two steps? - ANS-Check
electrical wire for tighteness and clean the blower components
How is temperature rise determined? - ANS-Placing thermometer in the return and
supply plenums while the furnace is running
What tool should be used to clean the outside of the heat exchanger? - ANS-Soft Brush
How many heat exchangers do Natural Draft Furnace have? - ANS-One
How is Delta Temperature measured? and what should it match? - ANS-Supply Air
minus Return Air, It must not be less or more than Manufacturers Rating Plate
In a high efficiency furnace, which heat exchanger does the Supply air pass through
first? - ANS-The Secondary
What proves that your Induce blower is functional? - ANS-The pressure switch
How is Hot Surface Igniter diagnosed? - ANS-Connect leads to both wires, check for
voltage and Resistance
How is a belt motor in a furnace maintained? - ANS-Must be Oiled and Alignment
Where is the Automatic Damper located? - ANS-Down stream of the draft hood
What purpose does a Automatic damper serve? How does it work? - ANS-Reduce heat
loss up the chimney and it opens when burners fire and closes during the off cycle
What is Static Pressure in a furnace?, how is it measured?, and what standard must it
meet? - ANS-The pressure in the furnace at 90 degrees. It's measured with a
manometer It must meet Manufacturers Rating plate standard
