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73)
73)
How are Category IV furnaces generally vented?
A)
Stainless steel
B)
Rigid metal
C)
Flexible foil
D)
PVC venting
Answer:
D
Explanation:
A)
B)
C)
D)
74)
74)
If the temperature rise of a furnace is too low, how can it be increased?
A)
Reducing the air flow
B)
Increasing the voltage to the furnace
C)
Increasing the manifold pressure by ½ in wc over the data plate recommendation
D)
Increasing the air flow
Answer:
A
Explanation:
A)
B)
C)
D)
75)
75)
The difference between vent sizing for natural-draft appliances and fan-assisted appliances is
that:
A)
Columns for fan-assisted appliances list both a minimum and a maximum appliance
capacity for each vent size.
B)
Vents for fan-assisted appliances are typically larger in diameter for the same BTU capacity.
C)
Vents for fan-assisted appliances are always the same size as the connector on the furnace.
D)
Columns for fan-assisted appliances list sizes for both vertical and horizontal installation.
Answer:
A
Explanation:
A)
B)
C)
D)
76)
76)
Why should the technician check the furnace door safety switch after installation?
A)
To sync it with the indoor blower
B)
To prevent the furnace from operating with the door removed
C)
To check the furnace interior for defects in the outgoing vents
D)
To test for furnace flashback
Answer:
B
Explanation:
A)
B)
C)
D)
21
77)
77)
What regulates the draft through the heat exchanger and prevents downdrafts from blowing into
the heat exchanger on natural-draft gas furnaces?
A)
The induced draft blower
B)
The draft regulator
C)
The draft diverter
D)
The barometric damper
Answer:
C
Explanation:
A)
B)
C)
D)
78)
78)
Too much primary air or will cause:
A)
Delayed ignition.
B)
The high limit to open.
C)
Higher-than-normal temperature rise.
D)
Flame rollout.
Answer:
A
Explanation:
A)
B)
C)
D)
79)
79)
Which component failure could keep the fan from operating during the heating cycle on a
traditional standing pilot gas furnace?
A)
A defective limit switch
B)
An open coil on the fan relay
C)
A bad thermostat wire connection on the G terminal
D)
A defective fan switch
Answer:
D
Explanation:
A)
B)
C)
D)
80)
80)
What is the first step in the operational sequence?
A)
The igniter is energized.
B)
The thermostat calls for heat.
C)
The draft switch closes.
D)
The burners light.
Answer:
B
Explanation:
A)
B)
C)
D)
22
81)
81)
Which failure could cause nothing to happen when the thermostat is set to heat?
A)
A bad gas valve
B)
A tripped circuit breaker
C)
A bad igniter
D)
A defective draft switch
Answer:
B
Explanation:
A)
B)
C)
D)
82)
82)
Hot Surface Ignition System (HSI) controls lockout after how many unsuccessful attempts?
A)
The controls do not lock out.
B)
Two attempts
C)
Three or more attempts
D)
One attempt
Answer:
C
Explanation:
A)
B)
C)
D)
83)
83)
How can the safety lockout be reset?
A)
Recirculating products of combustion
B)
Turning on the power to the ignition module
C)
Purging the combustion air blower
D)
Setting the thermostat below room temperature
Answer:
D
Explanation:
A)
B)
C)
D)
84)
84)
When is the igniter energized on an induced draft furnace that uses hot surface ignition?
A)
On the initial call for heat
B)
At the same time the induced draft blower is energized
C)
At the same time the gas valve is energized
D)
After the draft switch closes to prove the draft
Answer:
D
Explanation:
A)
B)
C)
D)
23
85)
85)
Soot accumulation on the heat exchanger is:
A)
Normal over a period of years.
B)
Caused by incomplete combustion.
C)
A natural protective layer for the inside of the heat exchanger.
D)
Not possible with a gas furnace.
Answer:
B
Explanation:
A)
B)
C)
D)
86)
86)
When is the induced draft blower energized on an induced-draft furnace that uses hot surface
ignition?
A)
After the igniter has been energized
B)
On the initial call for heat
C)
At the same time the gas valve is energized
D)
After the draft switch closes to prove the draft
Answer:
B
Explanation:
A)
B)
C)
D)
87)
87)
Lack of secondary air or a stopped up vent will cause:
A)
Delayed ignition.
B)
Higher-than-normal temperature rise.
C)
The high limit to open.
D)
Flame rollout.
Answer:
D
Explanation:
A)
B)
C)
D)
88)
88)
An open door switch on a gas furnace will cause:
A)
A complete system shutdown–no system operation at all.
B)
The door open alarm to sound, but will not affect system operation.
C)
The indoor blower to shut down, but will not affect the combustion process.
D)
The combustion process to shut down, but will not affect the indoor blower.
Answer:
A
Explanation:
A)
B)
C)
D)
24
89)
89)
What causes the little pops and ticking that can be heard in some furnaces before the blower
comes on?
A)
Mechanical rattles from an unbalanced indoor blower
B)
Small quantities of water in the gas
C)
Small concentrated pockets of gas that explode
D)
Expansion of the heat exchanger as it heats up
Answer:
D
Explanation:
A)
B)
C)
D)
90)
90)
What is the most likely cause of flames that are lifting off the burner?
A)
Misaligned burner
B)
Too little primary air
C)
Excessive combustion chamber draft
D)
Too much primary air
Answer:
D
Explanation:
A)
B)
C)
D)
91)
91)
When is the gas valve energized on an induced-draft furnace that uses hot surface ignition?
A)
After the draft switch closes to prove the draft
B)
At the same time the induced draft blower is energized
C)
After the igniter has been energized
D)
On the initial call for heat
Answer:
C
Explanation:
A)
B)
C)
D)
92)
92)
What components of the oil burner are responsible for atomizing the oil?
A)
The oil pump and nozzle
B)
The oil slinger and collection cup
C)
The fan, air tube, and turbulator
D)
The ignition transformer and electrodes
Answer:
A
Explanation:
A)
B)
C)
D)
25
93)
93)
The grades of fuel oil are 1 through 6 with:
A)
6 being the lightest and most distilled and having the lowest heating capacity.
B)
1 being the lightest and most distilled and having the highest heating capacity.
C)
6 being the lightest and most distilled and having the highest heating capacity.
D)
1 being the lightest and most distilled and having the lowest heating capacity.
Answer:
D
Explanation:
A)
B)
C)
D)
94)
94)
How are oil burner nozzles rated?
A)
Cone shape, GPH, and BTUH
B)
Spray angle, BTUH, and GPH
C)
Cone shape, spray angle, and GPH
D)
GPH, VUS, and GPH
Answer:
C
Explanation:
A)
B)
C)
D)
95)
95)
The heating capacity of number 2 fuel oil is approximately:
A)
140,000 BTU per gallon.
B)
100,000 BTU per gallon.
C)
120,000 BTU per gallon.
D)
160,000 BTU per gallon.
Answer:
A
Explanation:
A)
B)
C)
D)
96)
96)
Which of the following statements is TRUE about a Grade 1 fuel oil?
A)
The oil consists of 1 percent carbon.
B)
The oil consists of 1 percent sulfur.
C)
The oil consists of 100 percent residuals.
D)
The oil consists of 100 percent light distillates.
Answer:
D
Explanation:
A)
B)
C)
D)
26
97)
97)
The heat in the combustion chamber is reflected and concentrated by the:
A)
Concentrator.
B)
Refractory.
C)
Heat exchanger.
D)
Reflector.
Answer:
B
Explanation:
A)
B)
C)
D)
98)
98)
Which is the result of the twisting motion of the heated helix?
A)
Contraction of the bimetallic element
B)
Expansion of the bimetallic element
C)
Activation of the limit control switch
D)
Activation of the emergency cut-off switch
Answer:
C
Explanation:
A)
B)
C)
D)
99)
99)
What is oil viscosity?
A)
Viscosity is a measure of the heating capacity of the oil.
B)
Viscosity is a measure of the thickness of the oil.
C)
Viscosity is a measure of the relative lubricity of the oil.
D)
Viscosity is an oil additive that determines how freely oil flows.
Answer:
B
Explanation:
A)
B)
C)
D)
100)
100)
The output pressure of a high-pressure oil pump used in residential oil-fired furnaces is:
A)
200 to 450 psi.
B)
100 to 200 psi.
C)
Up to 1,000 psi.
D)
50 to 100 psi.
Answer:
B
Explanation:
A)
B)
C)
D)
27
101)
101)
Which of the following features increases overall efficiency to between 83 and 89%?
A)
Barometric damper
B)
Flame-retention burner
C)
Sealed combustion chamber
D)
Aquastat controller
Answer:
C
Explanation:
A)
B)
C)
D)
102)
102)
A major difference between the operation of an oil furnace and a gas furnace is that:
A)
Oil furnaces do not burn as hot as gas furnaces.
B)
It is more difficult to set up a gas furnace to burn cleanly.
C)
The oil must be atomized before ignition.
D)
Oil has a lower heat content value than gas.
Answer:
C
Explanation:
A)
B)
C)
D)
103)
103)
Sealed combustion oil furnaces use:
A)
Special sealed airtight barometric draft regulators.
B)
High static oil burners.
C)
A separate bottled oxygen supply for cleaner combustion.
D)
No vent because the combustion chamber is sealed.
Answer:
B
Explanation:
A)
B)
C)
D)
104)
104)
The cad cell senses the flames by:
A)
Dropping in resistance when exposed to heat.
B)
Dropping in resistance when exposed to light.
C)
Increasing in resistance when exposed to heat.
D)
Increasing in resistance when exposed to light.
Answer:
B
Explanation:
A)
B)
C)
D)
28
105)
105)
What allows for adjustment in the tertiary opening to enable fine-tuning of the burner?
A)
Nozzle
B)
Variable burner head
C)
Flame stabilizer
D)
Spray angle
Answer:
B
Explanation:
A)
B)
C)
D)
106)
106)
With what must the nozzle spray pattern be compatible for proper mixing?
A)
Burner air pattern
B)
Spray angle
C)
Mix of oil and air
D)
Orifice
Answer:
A
Explanation:
A)
B)
C)
D)
107)
107)
Which grade of fuel oil has the highest viscosity?
A)
All fuel oil has the same viscosity because it requires the same additives.
B)
Only industrial duty fuel oil is required to have viscosity.
C)
Number 6
D)
Number 1
Answer:
C
Explanation:
A)
B)
C)
D)
108)
108)
Which of the following grades of oil are the grades of fuel oil primarily used for comfort heating
applications?
A)
3 and 4
B)
1 and 6
C)
1 and 2
D)
5 and 6
Answer:
C
Explanation:
A)
B)
C)
D)
29
109)
109)
Which of the following measures is the minimum steam pressure for a high-pressure boiler?
A)
50 psi
B)
15 psi
C)
150 psi
D)
160 psi
Answer:
B
Explanation:
A)
B)
C)
D)
110)
110)
Select the functions that the primary control performs. You may select more than one.
A)
Provides over-temperature-limit protection
B)
Provides flame safety shutdown
C)
Controls ignition transformer
D)
Provides 24 V to control external equipment
E)
Starts and stops oil burner motor
Answer:
B, C, E
Explanation:
A)
B)
C)
D)
E)
111)
111)
What must be used to test the output of the ignition transformer?
A)
High-voltage probe
B)
Draft leads
C)
Standard set of leads
D)
Regular multimeter leads
Answer:
A
Explanation:
A)
B)
C)
D)
112)
112)
What smoke spot number represents correct combustion in newer burners?
A)
1 or less
B)
0
C)
2 or less
D)
1 or more
Answer:
A
Explanation:
A)
B)
C)
D)
30
113)
113)
Which style of burner usually operates with a higher flue gas CO2 percentage?
A)
Newer gun burners
B)
Flame retention burners
C)
The CO2 should be around 12 percent with all oil burners.
D)
Older gun burners
Answer:
B
Explanation:
A)
B)
C)
D)
114)
114)
As the refractory temperature increases, the combustion efficiency:
A)
Decreases.
B)
Increases.
C)
Fluctuates.
D)
Stays the same.
Answer:
B
Explanation:
A)
B)
C)
D)
115)
115)
What is the maximum level of the normal CO range?
A)
9 ppm
B)
1 ppm
C)
36 ppm
D)
10 ppm
Answer:
A
Explanation:
A)
B)
C)
D)
116)
116)
The normal fan switch off temperature range is:
A)
125130°F.
B)
140150°F.
C)
95100°F.
D)
8590°F.
Answer:
C
Explanation:
A)
B)
C)
D)
31
117)
117)
When testing combustion efficiency, the technician should measure:
A)
Ambient temperature, return air temperature, supply air temperature, and stack
temperature.
B)
Stack temperature, ambient temperature, and CO2 flue gas percentage.
C)
Oil pump pressure, stack temperature, ambient temperature, and CO2 flue gas percentage.
D)
Stack temperature, flue gas density, and flue gas water percentage.
Answer:
B
Explanation:
A)
B)
C)
D)
118)
118)
How does excess air affect the vent gas CO2 percentage?
A)
Excess air completely eliminates CO2 in the vent gas.
B)
Excess air increases the vent gas CO2 percentage.
C)
Excess air has no effect on vent gas CO2 percentage.
D)
Excess air reduces the vent gas CO2 percentage.
Answer:
D
Explanation:
A)
B)
C)
D)
119)
119)
What is the last step in the operational sequence of the typical oil-fired furnace?
A)
The flame shuts down.
B)
The indoor blower turns off.
C)
The fan switch contacts open.
D)
The heat exchanger cools.
Answer:
B
Explanation:
A)
B)
C)
D)
120)
120)
On a single-pipe system, it is necessary to purge air from which component?
A)
Solenoid valve
B)
Oil filter
C)
Nozzle
D)
Inlet strainer
Answer:
B
Explanation:
A)
B)
C)
D)
32
121)
121)
What allows the safety relay to operate?
A)
Increasing the current flow
B)
Shutting off the burner
C)
Heating up the heat exchanger
D)
Decreasing the current flow
Answer:
A
Explanation:
A)
B)
C)
D)
122)
122)
What is the net stack temperature?
A)
The temperature difference between the stack temperature and the ambient temperature
B)
The temperature difference between the over-fire temperature and the stack temperature
C)
The sum of the stack temperature and the ambient temperature
D)
The temperature difference between the over-fire temperature and the ambient temperature
Answer:
A
Explanation:
A)
B)
C)
D)
123)
123)
Which type of burner has the highest common operating percentage of CO2?
A)
Rotary wall flame burner
B)
Flame-retention gun burner
C)
Newer-style gun burners
D)
Old-style gun burners
Answer:
A
Explanation:
A)
B)
C)
D)
124)
124)
What is the purpose of excess combustion air?
A)
Excess air is added to improve combustion efficiency.
B)
Excess air improves the over-fire draft.
C)
Excess air is added to increase the combustion temperature.
D)
Excess air is added to ensure complete combustion.
Answer:
D
Explanation:
A)
B)
C)
D)
33
125)
125)
Newer-style gun burners with special air-handling parts should be set in what range of CO2
percentage?
A)
79 percent
B)
1113 percent
C)
911 percent
D)
03 percent
Answer:
C
Explanation:
A)
B)
C)
D)
126)
126)
How does soot accumulation on the inside of the heat exchanger affect system efficiency?
A)
The soot acts like an insulator on the inside of the heat exchanger, thereby reducing
efficiency.
B)
The soot provides extra fuel during the high-fire stage, thereby increasing efficiency.
C)
The soot increases the heat exchanger internal resistance, thereby increasing efficiency.
D)
The soot acts like an insulator on the inside of the heat exchanger, thereby increasing
efficiency.
Answer:
A
Explanation:
A)
B)
C)
D)
127)
127)
In a two-pipe system, the pump forces air down what?
A)
Combustion chamber
B)
Oil-return line
C)
Clear plastic hose
D)
Supply line
Answer:
B
Explanation:
A)
B)
C)
D)
128)
128)
How can a range of heating capacities be achieved with the same burner?
A)
Moving the oil storage tank
B)
Using shorter cycles
C)
Changing the nozzle
D)
Moving the furnace
Answer:
C
Explanation:
A)
B)
C)
D)
34
129)
129)
When the oil tank is located indoors, it must be located:
A)
At least 5 ft away from any flames or heat-producing equipment.
B)
In a location that is not subjected to freezing temperatures.
C)
At least 10 ft away from any flames or heat-producing equipment.
D)
In a separate room.
Answer:
A
Explanation:
A)
B)
C)
D)
130)
130)
What is the difference in equivalent length of an 8-in connector between a 45-degree ell and a
90-degree ell?
A)
8 ft
B)
9 ft
C)
7 ft
D)
6 ft
Answer:
C
Explanation:
A)
B)
C)
D)
131)
131)
If combustion air openings pass through vertical ducts with 4,000 BTU input, how large should
the openings measure?
A)
1 sq in
B)
3 sq in
C)
2 sq in
D)
4 sq in
Answer:
A
Explanation:
A)
B)
C)
D)
132)
132)
If combustion air openings pass through horizontal ducts with 4,000 BTU input, how large should
the openings measure?
A)
2 sq in
B)
1 sq in
C)
3 sq in
D)
4 sq in
Answer:
A
Explanation:
A)
B)
C)
D)
35
133)
133)
What type of material must be used for a chimney connector in a crawlspace?
A)
Type B vent material
B)
Type L vent material
C)
20 gauge single-wall metal
D)
Type BW vent material
Answer:
B
Explanation:
A)
B)
C)
D)
134)
134)
The firing rate of a furnace with a 0.75 gph nozzle is:
A)
75,000 BTU per hour.
B)
105,000 BTU per hour.
C)
150,000 BTU per hour.
D)
7,500 BTU per hour.
Answer:
B
Explanation:
A)
B)
C)
D)
135)
135)
The bypass plug is removed for the operation of what kind of system?
A)
Three-pipe system
B)
Two-pipe system
C)
One-pipe system
D)
No-pipe system
Answer:
C
Explanation:
A)
B)
C)
D)
136)
136)
What national standards organization publishes standard 31, a reference for installing oil
furnaces?
A)
NICE, National Institute of Clean Energy
B)
NFPA, National Fire Protection Association
C)
NIST, National Institute of Standards and Technology
D)
NOFA, National Oil Furnace Manufacturers Association
Answer:
B
Explanation:
A)
B)
C)
D)
36
137)
137)
A two-pipe system should be installed with the suction at the oil pump greater than what
measure?
A)
12 in Hg
B)
6 in Hg
C)
16 in Hg
D)
17 in Hg
Answer:
B
Explanation:
A)
B)
C)
D)
138)
138)
What is the configuration most appropriate for a utility room or closet with the duct in the
crawlspace?
A)
Downflow
B)
Lowboy
C)
Upflow
D)
Horizontal
Answer:
A
Explanation:
A)
B)
C)
D)
139)
139)
What is a multiposition furnace?
A)
It is a vent-free oil furnace that can be installed anywhere.
B)
It is a furnace that can be converted to a boiler.
C)
It is a furnace that can be used in most any position.
D)
It is a furnace that can use multiple types of fuels.
Answer:
C
Explanation:
A)
B)
C)
D)
140)
140)
Which distance is the minimum amount of clearance for the flue pipe of an oil-fired furnace?
A)
6 in
B)
9 in
C)
36 in
D)
24 in
Answer:
B
Explanation:
A)
B)
C)
D)
37
141)
141)
When installing an oil-fired furnace in a confined space with a firing rate of 100,000 Btuh, what is
the minimum free air opening required if the combustion air vents are directly communicating
with the outside?
A)
100,000/5,000 = 20 sq in for each grille
B)
100,000/1,000 = 100 sq in for each grille
C)
100,000/2,000 = 50 sq in for each grille
D)
100,000/4,000 = 25 sq in for each grille
Answer:
A
Explanation:
A)
B)
C)
D)
142)
142)
What types of appliances may oil furnaces be common vented with?
A)
Oil furnaces may not be common vented.
B)
Only other oil-burning appliances
C)
Only oil- or gas-burning appliances
D)
Only oil- or solid-fuel-burning appliances
Answer:
B
Explanation:
A)
B)
C)
D)
143)
143)
What should a technician do if called to work on an oil burner with a tripped safety reset?
A)
Replace the cad cell.
B)
Check the combustion chamber for unburned oil.
C)
Push the reset button and closely observe the ignition sequence.
D)
Replace the oil burner primary control.
Answer:
B
Explanation:
A)
B)
C)
D)
144)
144)
What is the first thing to do if the oil burner has been delivering oil and it has not been igniting?
A)
Clean the excess oil out of the combustion chamber.
B)
Clean the primary control.
C)
Check the wiring.
D)
Check the transformer primary voltage.
Answer:
A
Explanation:
A)
B)
C)
D)
38
145)
145)
The resistance of a good cad cell when it is in the dark should be:
A)
30 to 1,000.
B)
5,000 to 10,000.
C)
1,000 to 5,000.
D)
100,000 or higher.
Answer:
D
Explanation:
A)
B)
C)
D)
146)
146)
Ignition transformers operate at high temperatures, which can cause cracking and moisture
absorption, resulting in which of the following?
A)
A grounded winding
B)
A shorted winding
C)
A good winding
D)
An open winding
Answer:
A
Explanation:
A)
B)
C)
D)
147)
147)
What is the minimum furnace size for which the fire department should be called to be on
standby before lighting the burner when the refractory has been soaked with oil?
A)
1.5 gph
B)
4.5 gph
C)
3.5 gph
D)
2.5 gph
Answer:
D
Explanation:
A)
B)
C)
D)
148)
148)
How is soot formed?
A)
From a clogged bypass plug
B)
From a suction leak
C)
From incomplete combustion
D)
From an excessive over-fire draft
Answer:
C
Explanation:
A)
B)
C)
D)
39
149)
149)
The burner motor runs, but the oil pump does not produce pressure. This can be caused by:
A)
A defective burner motor centrifugal switch.
B)
A defective oil pump drive coupling.
C)
A plugged oil nozzle.
D)
A defective ignition transformer.
Answer:
B
Explanation:
A)
B)
C)
D)
150)
150)
What might be the problem if the furnace runs, but with short cycles?
A)
Defective relay protector
B)
Defective fan controller
C)
Cracked heat exchanger
D)
Improper heat anticipator setting
Answer:
D
Explanation:
A)
B)
C)
D)
151)
151)
What is a potential problem for the electrodes?
A)
Clogged output terminals
B)
Cracked porcelain insulator
C)
Narrow nozzle orifice
D)
Lack of spark
Answer:
B
Explanation:
A)
B)
C)
D)
152)
152)
What should be done to prepare an oil pump for operation in a one-pipe oil delivery system?
A)
The oil burner must be set for low speed.
B)
The oil burner motor must be set for high speed.
C)
The internal bypass plug should be installed.
D)
The internal bypass plug should be removed.
Answer:
D
Explanation:
A)
B)
C)
D)
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