GAS HEAT ESCO EXAM QUESTIONS
AND ANSWERS
What instrument would a technician use to measure return airflow to a furnace? -
Answer-anemometer
A furnace with a hot surface igniter will not light. Before changing the igniter the
technician should: - Answer-check voltage to igniter
A technician starts a standing pilot furnace and notices on main ignition the flames "roll
out". The technician suspects: - Answer-a faulty vent
A technician servicing an LP gas furnace notices a tag stating it was converted from
natural gas. He finds large amounts of soot in the heat exchanger. What could be the
cause of this soot? - Answer-Orifice (spud) too large
A customer tells a technician that his six month old furnace stops heating before the
residence is warm. This happens only on very cold nights. The technician light the
furnace, and tries to adjust the gas valve, but the flames do not change. He suspect: -
Answer-a defective gas valve regulator
A standing pilot furnace has a bi-metal fan/limit control. What are the factory settings? -
Answer-Fan on 125 F / Fan off 110 F / Limit cut out 200 F
Type B Vent pipe is constructed with an inner pipe and outer pipe. The inner pipe is
made of: - Answer-Aluminum
On a dedicated vent system, a fire stop support plate is located: - Answer-where it
passes through a ceiling
When venting Category I furnaces, it is sometimes necessary to increase the vent pipe
size. The proper location to adapt to the larger vent is: - Answer-at the furnace
connection
You are installing 1/2" and 3/4" black iron pipe to a natural gas furnace. What is the
approximate number of threads to cut? - Answer-8-10
The proper name of the tool used to clean the inside edge of steel pipe is a: - Answer-
reamer
The proper name of the tool used to cut the threads of a steel pipe is a: - Answer-die
Clevis, ring, and single hook are types of ___ - Answer-hanger to support gas piping
, You are installing two sections of a rectangular sheet metal duct to the main supply line.
What connectors are used to secure sections of the trunk line? - Answer-S connectors
and drive clips
Metal ductwork tends to transmit noise and fan vibrations to conditioned spaces in
residential installations. What type of connectors are specified to control this? - Answer-
Flex connectors
Duct wrap is used to insulate round metal ducts. What is the approximate R-vale for
"one inch" of this insulation? - Answer-R=3.0 for one inch and increases as "inches"
increase
A Category I natural gas furnace has a typical air temperature rise of: - Answer-40 F -
70 F
A technician connects the electrical circuit to an 80,000 BTU gas furnace with a 3-ton
cooling system. The fan motor is rated 1/3 HP @ 120 VAC. What size conductor would
normally be used? (copper conductors) - Answer-12-14 AWG
A GFCI circuit breaker detects: - Answer-current leaks to ground
A homeowner complained that his furnace makes a loud bang upon ignition. The
technician decides to check the gas pressure and finds 3.2 in. WC at the manifold. The
technician should: - Answer-Check supply gas pressure
How much current does a typical flame sensor produce? - Answer-1-30 microamps
A typical vent stack temperature on a NATURAL DRAFT furnace is: - Answer-350 F -
450 F
A customer complains that a 2-year old gas furnace will not light. The technician
determines that the furnace locks out will attempting to light. He reads 19 VAC at the
gas valve and concludes: - Answer-Transformer could be faulty
The pilot assembly orifice of a spark ignition furnace is completely clogged. The
technician should: - Answer-replace it
Carbon monoxide is dangerous. What percentage of CO is acceptable in a sample of
the flue gas? - Answer-0.04%
A technician starts up a 5 year old natural gas furnace. The main burner lights and after
60 seconds the blower fan comes on, but the burner flames wavers in one corner. The
technician suspects: - Answer-A faulty heat exchanger
A technician starts a spark type ignition furnace. The main burners light, but the spark
igniter continues to spark. After 60 seconds, the flower fan comes on and the burner
AND ANSWERS
What instrument would a technician use to measure return airflow to a furnace? -
Answer-anemometer
A furnace with a hot surface igniter will not light. Before changing the igniter the
technician should: - Answer-check voltage to igniter
A technician starts a standing pilot furnace and notices on main ignition the flames "roll
out". The technician suspects: - Answer-a faulty vent
A technician servicing an LP gas furnace notices a tag stating it was converted from
natural gas. He finds large amounts of soot in the heat exchanger. What could be the
cause of this soot? - Answer-Orifice (spud) too large
A customer tells a technician that his six month old furnace stops heating before the
residence is warm. This happens only on very cold nights. The technician light the
furnace, and tries to adjust the gas valve, but the flames do not change. He suspect: -
Answer-a defective gas valve regulator
A standing pilot furnace has a bi-metal fan/limit control. What are the factory settings? -
Answer-Fan on 125 F / Fan off 110 F / Limit cut out 200 F
Type B Vent pipe is constructed with an inner pipe and outer pipe. The inner pipe is
made of: - Answer-Aluminum
On a dedicated vent system, a fire stop support plate is located: - Answer-where it
passes through a ceiling
When venting Category I furnaces, it is sometimes necessary to increase the vent pipe
size. The proper location to adapt to the larger vent is: - Answer-at the furnace
connection
You are installing 1/2" and 3/4" black iron pipe to a natural gas furnace. What is the
approximate number of threads to cut? - Answer-8-10
The proper name of the tool used to clean the inside edge of steel pipe is a: - Answer-
reamer
The proper name of the tool used to cut the threads of a steel pipe is a: - Answer-die
Clevis, ring, and single hook are types of ___ - Answer-hanger to support gas piping
, You are installing two sections of a rectangular sheet metal duct to the main supply line.
What connectors are used to secure sections of the trunk line? - Answer-S connectors
and drive clips
Metal ductwork tends to transmit noise and fan vibrations to conditioned spaces in
residential installations. What type of connectors are specified to control this? - Answer-
Flex connectors
Duct wrap is used to insulate round metal ducts. What is the approximate R-vale for
"one inch" of this insulation? - Answer-R=3.0 for one inch and increases as "inches"
increase
A Category I natural gas furnace has a typical air temperature rise of: - Answer-40 F -
70 F
A technician connects the electrical circuit to an 80,000 BTU gas furnace with a 3-ton
cooling system. The fan motor is rated 1/3 HP @ 120 VAC. What size conductor would
normally be used? (copper conductors) - Answer-12-14 AWG
A GFCI circuit breaker detects: - Answer-current leaks to ground
A homeowner complained that his furnace makes a loud bang upon ignition. The
technician decides to check the gas pressure and finds 3.2 in. WC at the manifold. The
technician should: - Answer-Check supply gas pressure
How much current does a typical flame sensor produce? - Answer-1-30 microamps
A typical vent stack temperature on a NATURAL DRAFT furnace is: - Answer-350 F -
450 F
A customer complains that a 2-year old gas furnace will not light. The technician
determines that the furnace locks out will attempting to light. He reads 19 VAC at the
gas valve and concludes: - Answer-Transformer could be faulty
The pilot assembly orifice of a spark ignition furnace is completely clogged. The
technician should: - Answer-replace it
Carbon monoxide is dangerous. What percentage of CO is acceptable in a sample of
the flue gas? - Answer-0.04%
A technician starts up a 5 year old natural gas furnace. The main burner lights and after
60 seconds the blower fan comes on, but the burner flames wavers in one corner. The
technician suspects: - Answer-A faulty heat exchanger
A technician starts a spark type ignition furnace. The main burners light, but the spark
igniter continues to spark. After 60 seconds, the flower fan comes on and the burner
