hvacr gas heating esco Latest Update 2024-2025
Actual Exam from Credible Sources with 180
Questions and Verified Correct Answers Golden
Ticket to Guaranteed A+ Verified by Professor
A "spud" or burner orifice: - CORRECT ANSWER: meters gas to the burner
A BTU is the amount of heat required to raise the temperature of one pound of water: -
CORRECT ANSWER: one degree Fahrenheit
A Category I natural gas furnace has a typical air temperature rise of: - CORRECT
ANSWER: 40 F - 70 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: - CORRECT ANSWER: Transformer could be faulty
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: -
CORRECT ANSWER: a defective gas valve regulator
A dedicated vent system: - CORRECT ANSWER: is the only vent for an appliance
A furnace nameplate specifies a temperature rise of 40 - 70 degrees. Temperature
measurements indicate a rise of 80 degrees. The most appropriate action is to: -
CORRECT ANSWER: increase fan speed
A furnace nameplate specifies a temperature rise of 40 to 70 degrees. Temperature
measurements indicate a rise of 80 degrees. The most appropriate action is to: -
CORRECT ANSWER: increase fan speed
,A furnace with a hot surface igniter will not light. Before changing the igniter the
technician should: - CORRECT ANSWER: check voltage to igniter
A gas furnace has an electronic control board. How is the fan cycled during heating? -
CORRECT ANSWER: time
A gas furnace has an induced draft fan. Which switch must operate properly before
ignition sequence starts? - CORRECT ANSWER: differential air pressure
A gas furnace to be installed in a garage. The national standards requires that the
burners and ignition must be located ____ above the floor: - CORRECT ANSWER: 18
inches
A gas valve with 100% shut-off meCORRECT ANSWER: - CORRECT ANSWER: gas to
a pilot and manifold is shut off
A GFCI circuit breaker detects: - CORRECT ANSWER: current leaks to ground
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is: - CORRECT ANSWER: Temperature on/ Temperature off
A good thermocouple should read approximately ____ on a D.C. meter - CORRECT
ANSWER: 30 millivolts (mV)
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: - CORRECT ANSWER: Check supply gas pressure
A natural gas furnace usually requires _____ gas pressure AT the manifold and burners.
What should the inlet pressure be to the manifold? - CORRECT ANSWER: 3.5 in WC
inlet- 5-7 in WC
, A spark igniter operates at ____ VAC - CORRECT ANSWER: 10,000 and higher
A standing pilot furnace has a bi-metal fan/limit control. What are the factory settings? -
CORRECT ANSWER: Fan on 125 F / Fan off 110 F / Limit cut out 200 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) - CORRECT ANSWER: 12-14 AWG
A technician determines that a natural gas furnace has a defective heat exchanger. The
technician should: - CORRECT ANSWER: Inform the home owner and turn the gas off.
A technician is installing a copper elbow on LP gas line; what should be used? -
CORRECT ANSWER: 15% silver solder
A technician is using an extension ladder to work on roof top unit. The top of the ladder
should extend _____ beyond the support point. - CORRECT ANSWER: 3 feet
A technician need to run thermostat wire 75 feet. To avoid a voltage drop, the technician
should use: - CORRECT ANSWER: 18 AWG
A technician reads 0 ohms between the common and low speed wires on a 120 VAC
furnace motor. From this the technician determines that the winding is: - CORRECT
ANSWER: shorted
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? - CORRECT ANSWER: Orifice (spud) too large
A technician solders a spade connector to a wire. What type of solder should he use? -
CORRECT ANSWER: 95/5
Actual Exam from Credible Sources with 180
Questions and Verified Correct Answers Golden
Ticket to Guaranteed A+ Verified by Professor
A "spud" or burner orifice: - CORRECT ANSWER: meters gas to the burner
A BTU is the amount of heat required to raise the temperature of one pound of water: -
CORRECT ANSWER: one degree Fahrenheit
A Category I natural gas furnace has a typical air temperature rise of: - CORRECT
ANSWER: 40 F - 70 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: - CORRECT ANSWER: Transformer could be faulty
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: -
CORRECT ANSWER: a defective gas valve regulator
A dedicated vent system: - CORRECT ANSWER: is the only vent for an appliance
A furnace nameplate specifies a temperature rise of 40 - 70 degrees. Temperature
measurements indicate a rise of 80 degrees. The most appropriate action is to: -
CORRECT ANSWER: increase fan speed
A furnace nameplate specifies a temperature rise of 40 to 70 degrees. Temperature
measurements indicate a rise of 80 degrees. The most appropriate action is to: -
CORRECT ANSWER: increase fan speed
,A furnace with a hot surface igniter will not light. Before changing the igniter the
technician should: - CORRECT ANSWER: check voltage to igniter
A gas furnace has an electronic control board. How is the fan cycled during heating? -
CORRECT ANSWER: time
A gas furnace has an induced draft fan. Which switch must operate properly before
ignition sequence starts? - CORRECT ANSWER: differential air pressure
A gas furnace to be installed in a garage. The national standards requires that the
burners and ignition must be located ____ above the floor: - CORRECT ANSWER: 18
inches
A gas valve with 100% shut-off meCORRECT ANSWER: - CORRECT ANSWER: gas to
a pilot and manifold is shut off
A GFCI circuit breaker detects: - CORRECT ANSWER: current leaks to ground
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is: - CORRECT ANSWER: Temperature on/ Temperature off
A good thermocouple should read approximately ____ on a D.C. meter - CORRECT
ANSWER: 30 millivolts (mV)
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: - CORRECT ANSWER: Check supply gas pressure
A natural gas furnace usually requires _____ gas pressure AT the manifold and burners.
What should the inlet pressure be to the manifold? - CORRECT ANSWER: 3.5 in WC
inlet- 5-7 in WC
, A spark igniter operates at ____ VAC - CORRECT ANSWER: 10,000 and higher
A standing pilot furnace has a bi-metal fan/limit control. What are the factory settings? -
CORRECT ANSWER: Fan on 125 F / Fan off 110 F / Limit cut out 200 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) - CORRECT ANSWER: 12-14 AWG
A technician determines that a natural gas furnace has a defective heat exchanger. The
technician should: - CORRECT ANSWER: Inform the home owner and turn the gas off.
A technician is installing a copper elbow on LP gas line; what should be used? -
CORRECT ANSWER: 15% silver solder
A technician is using an extension ladder to work on roof top unit. The top of the ladder
should extend _____ beyond the support point. - CORRECT ANSWER: 3 feet
A technician need to run thermostat wire 75 feet. To avoid a voltage drop, the technician
should use: - CORRECT ANSWER: 18 AWG
A technician reads 0 ohms between the common and low speed wires on a 120 VAC
furnace motor. From this the technician determines that the winding is: - CORRECT
ANSWER: shorted
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? - CORRECT ANSWER: Orifice (spud) too large
A technician solders a spade connector to a wire. What type of solder should he use? -
CORRECT ANSWER: 95/5
