Name: 
 

ICE Practice



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

The resistance to air flow of ducts, coils, filters and other surfaces is called:
a.
velocity
c.
static pressure
b.
total pressure
d.
stratification
 

 2. 

Using an ohmmeter, you measure zero (0) ohms between "C" and "S" terminals. This most likely means:
a.
start winding is open
c.
internal overload is open
b.
start winding is shorted
d.
start winding is good
 

 3. 

A "start kit" for a compressor:
a.
decreases start winding resistance
c.
increases starting torque
b.
increases start winding resistance
d.
decreases starting torque
 

 4. 

Which of the following could cause head pressure to rise (cooling mode)?
a.
clogged filter
c.
non-condensable in the system
b.
a frosted evaporator
d.
plugged filter/drier
 

 5. 

How much heat (approximately) is produced by a 5 KW heater?
a.
5000
c.
10000
b.
7500
d.
17000
 

 6. 

The point at which a heatpump produces exactly 100% of the structure heat loss is called the:
a.
thermal balance point
c.
heating seasonal performance factor
b.
coefficient of performance
d.
equalization temperature
 

 7. 

What instrument is used to measure static pressure?
a.
inclined manometer
c.
mercury manometer
b.
velometer
d.
anemometer
 

 8. 

The purpose of the internal bleed port on some types of TXV is to:
a.
maintain full flow to the evaporator
c.
equalize pressures in the "on" cycle
b.
compensate for evaporator pressure drop
d.
equalize pressures in the "off" cycle
 

 9. 

Why must you energize the crankcase heat for at least 24 hours prior to starting a compressor that has been off for a long time?
a.
reduce the oil viscosity
c.
warm the compressor for easier starting
b.
reduce the amount of refrigerant trapped in the oil
d.
increase the oil viscosity
 

 10. 

One advantage of multi-tapped, direct drive PSC motors is:
a.
it is in constant operation
c.
the amp draw remains constant
b.
CFM changes are easily made
d.
it moves more air than a belt drive
 

 11. 

A device that removes the start capacitor from the circuit when a hermetic compressor reaches about 80% operating sped is the:
a.
impedance relay
c.
run capacitor
b.
centrifugal switch
d.
potential relay
 

 12. 

Which of the following can cause a frosted evaporator?
a.
bad compressor valves
c.
an undersized duct system
b.
high suction pressure
d.
an overcharged evaporator
 

 13. 

When checking a compressor motor with an ohmmeter, the highest reading would be from:
a.
start to common
c.
start to run
b.
main to run
d.
common to run
 

 14. 

The most likely reason for a compressor to cycle on and off while the condenser fan runs continuously is:
a.
low refrigerant charge
c.
open run winding
b.
low thermostat setting
d.
excessive load
 

 15. 

A blower motor is cycling on and off with the thermostat fan switch set to "on". The most likely cause is:
a.
start capacitor
c.
transformer
b.
motor overload
d.
wall thermostat
 

 16. 

Which of the following could cause the limit switch to open the circuit?
a.
fan control is open
c.
gas valve stuck shut
b.
transformer is burned out
d.
cracked heat exchanger
 

 17. 

What is the most accurate method f charging a heatpump in the heating mode?
a.
put the unit in cooling and charge by superheat
c.
charge to proper sub-cooling
b.
weigh in an exact charge
d.
charge by superheat in heating mode
 

 18. 

A continual roll-out on a gas furnace could be caused by
a.
a plugged heat exchanger
c.
excessive air flow
b.
excess combustion air
d.
low air flow
 

 19. 

What causes the liquid line defrost sensor on a heatpump to initiate a defrost?
a.
a discharge temperature at the compressor over 150F
c.
increase in liquid line temperature
b.
decrease in liquid line temperature
d.
constant, stable liquid line temperature
 

 20. 

Where should vibration eliminators be installed in a duct system?
a.
only on the supply
c.
after the first transition
b.
only on the return
d.
between the air handler and the first piece of duct
 

 21. 

The fan limit control senses
a.
temperature rise across the furnace
c.
supply air temperature
b.
return air temperature
d.
flue temperature
 

 22. 

When should suction line filter/driers be installed?
a.
when non-condensable are in the system
c.
installing a new system
b.
replacing a compressor following a burnout
d.
suction line pressure drop is below 5 PSIG
 

 23. 

The component used to reduce liquid entering a compressor is called a:
a.
receiver
c.
filter/drier
b.
accumulator
d.
muffler
 

 24. 

Most residences do not have mechanical fresh air intakes. Why?
a.
infiltration is used to meet fresh air needs
c.
most homes have fresh air controls
b.
air cleaners are used to supply fresh air
d.
local codes prevent it
 

 25. 

Lifting flames in a natural draft gas furnace is most likely caused by:
a.
low manifold pressure
c.
to much secondary air
b.
excessive gas pressure
d.
inadequate primary air
 

 26. 

Nominal manifold gas pressure on a natural gas, atmospheric draft furnace is:
a.
3"-4" wc
c.
3psig - 4 psig
b.
10"-12" wc
d.
10psig to 12psig
 

 27. 

The primary reason for sequencers on electric heat units is:
a.
increase inrush current
c.
ensure all elements are energized at the same time
b.
lower inrush current
d.
prevent all elements from being energized at the same time
 

 28. 

An increase in latent load on the evaporator will most likely cause:
a.
no change in evaporator pressure but an increase in condenser pressure
c.
a increase in evaporator and condenser pressure
b.
a decrease in evaporator and condenser pressure
d.
an increase in evaporator pressure and no change in condenser pressure
 

 29. 

Nominal indoor airflow through a heatpump evaporator is:
a.
200 CFM per ton
c.
400 CFM per ton
b.
300 CFM per ton
d.
500 CFM per ton
 

 30. 

An oil gun burner ignites the atomized oil by
a.
an ignition module
c.
ceramic hot surface
b.
a primary control
d.
electric arc between electrodes
 

 31. 

How would you best check to see if a fixed resistance crankcase heater is working with power supplied ?
a.
a megohmmeter
c.
a volt meter
b.
an ammeter
d.
an ohmmeter
 

 32. 

Which instrument(s) would you use to determine the total kilowatt output on an unlabeled electric air handler?
a.
voltmeter & thermometer
c.
ohmmeter and ammeter
b.
ohmmeter & voltmeter
d.
ammeter & voltmeter
 

 33. 

Which of the following occurs when a heatpump defrosts?
a.
refrigerant cycle reverses to cooling, indoor fan stops and defrost relay energizes
c.
defrost relay energizes, compressor stops, and supplemental heat energizes
b.
compressor stops, supplemental heat energizes, and outdoor fan stops
d.
refrigerant cycle reverses to cooling, outdoor fan stops, and supplemental heat energizes if available
 

 34. 

On a new start-up of a heatpump, in the heating mode, the unit will not accept the entire rated charge due to excessive discharge pressure. What is the most likely cause?
a.
improper refrigerant vapor line size
c.
insufficient air flow across the outdoor coil
b.
improper liquid line size
d.
insufficient air flow across the indoor coil
 

 35. 

A TXV equipped air-conditioner is experiencing low superheat, high suction pressure and excessive compressor sweating. What is the most likely cause?
a.
power element lost its charge
c.
condenser coil is dirty
b.
sensing bulb is loose
d.
undercharged
 

 36. 

A four (4) burner gas furnace is experiencing low flame height on all of the burners. What is most likely the problem?
a.
low manifold pressure
c.
oversized orifices
b.
flame impingement
d.
low primary air
 

 37. 

On a call for heat. a spark-type ignition furnace experiences spark, pilot lights, no further action. What is most likely happening?
a.
air switch did not close
c.
improper primary air
b.
improper sequence of ignition
d.
inadequate flame signal
 

 38. 

The suction pressure of an R-410a system at the service valve is measured at 132 PSIG. The line temperature at the same point is 56F. What is the superheat?
a.
20F
c.
15F
b.
10F
d.
45F
 

 39. 

An R-22 air-conditioner is operating with a liquid line pressure of 211 PSIG and liquid line temperature of 105F. What is the amount of sub-cooling?
a.
0F
c.
15F
b.
10F
d.
20F
 

 40. 

You find an iced over evaporator coil and the blower motor is hot and cycling on and off. The problem is most likely:
a.
a faulty motor or capacitor
c.
capillary restriction
b.
undercharge
d.
dirty condenser
 

 41. 

On a call to a heatpump in the cooling mode, the compressor runs but the outdoor fan does not. The fan motor and capacitor are determined to be okay. What is most likely?
a.
heat relay
c.
reversing valve
b.
contactor
d.
defrost control
 

 42. 

A furnace with four heaters rated 5KW at 240 VAC is getting only 208 VAC. What is the effect  on the furnace?
a.
increase BTUH output
c.
no decrease if the heaters are connected in parallel
b.
no decrease if the heaters are connected in series
d.
BTUH output will be reduced
 

 43. 

On start-up of a new heatpump, the unit heats satisfactorily but will not cool. The likely cause is
a.
outdoor check valve not closing
c.
indoor check valve open
b.
indoor check valve closed
d.
outdoor metering device is not metering
 

 44. 

In the heating mode, which of the following would contain high pressure, superheated vapor?
a.
suction line from reversing valve to compressor
c.
liquid line from indoor coil to outdoor coil
b.
discharge line from compressor to reversing valve
d.
outdoor coil
 

 45. 

In systems with TXV's on both indoor and outdoor coils, what purpose is served by the check valves?
a.
bypass indoor TXV in heating and outdoor TXV in cooling
c.
bypass both outdoor and indoor TXV's in cooling
b.
bypass outdoor TXV in heating and indoor TXV in cooling
d.
bypass both outdoor and indoor TXV's in heating
 

 46. 

In the heating mode, liquid refrigerant can be found in:
a.
suction line from indoor coil to outdoor coil
c.
the reversing valve
b.
the compressor
d.
liquid line from indoor coil to outdoor coil
 

 47. 

A room to room load calculation is necessary to:
a.
determine supply and return grill locations
c.
air distribution
b.
return air duct location
d.
velocity requirements
 

 48. 

An often overlooked adjustment on new systems is:
a.
heat anticipator
c.
high limit switch
b.
air pressure switch
d.
return air damper
 

 49. 

Before connecting gauges to stem type (rotolok) service vales, what position should the valves be before removing the caps?
a.
front seated and cracked
c.
back seated
b.
mid-seated
d.
completely front seated
 

 50. 

An oversized air-conditioner could result in:
a.
high superheat
c.
high condenser pressure
b.
excessive humidity
d.
increases evaporator pressure
 

 51. 

After new refrigerant piping has been installed and a leak check performed. the system should be evacuated to:
a.
30 inches
c.
500 microns or less
b.
29 inches
d.
1000 to 1500 microns
 

 52. 

On a service call to a new oil furnace, after resetting the primary control, the unit ignites and runs for approximately 45 seconds then stops. What is the most likely problem?
a.
dirty or faulty CAD cell
c.
wrong nozzle size
b.
excessive oil pressure
d.
closed primary safety switch
 

 53. 

The primary purpose for a lock-out on an ignition control is to prevent:
a.
excessive fuel build up
c.
burner short cycling
b.
furnace overheating
d.
damage to the ignition control system
 

 54. 

Which of the following is most important for proper vent operation?
a.
sufficient return air
c.
sufficient conditioned air
b.
adequate combustion air
d.
adequate supply air
 

 55. 

An electronic air cleaner should be wired to operate:
a.
only when the humidifier is running
c.
constantly
b.
only when the furnace blower is operating
d.
only on a call for heat
 

 56. 

On a service call to a new oil furnace, you find the pump pressure to 50 PSIG. What, if anything should yo do?
a.
increase the pump pressure
c.
reduce the pump pressure
b.
add a new fuel filter
d.
no action needed
 

 57. 

On a call to a straight cooling unit You find: head pressure above normal, temperature rise across the coil is 42F and sub-cooling is 5F. What is the probable cause?
a.
dirty outdoor coil
c.
clogged liquid line drier
b.
clogged indoor air filter
d.
refrigerant overcharge
 

 58. 

What is the purpose of a gas supply line drip leg?
a.
allows for the expansion of the gas
c.
drain condensation from the evaporator coil
b.
remove condensation from the heat exchangers of high efficiency furnaces
d.
prevent contamination from entering the gas valve
 

 59. 

When determining proper supply wire size, you must consider:
a.
voltage the unit is supplied with
c.
rating plate ampacity
b.
minimum circuit ampacity and length of the wire
d.
rating plate current only
 

 60. 

Which of the following is a safety concern when positioning a gas furnace?
a.
adequate gas supply
c.
clearance from combustible materials
b.
availability of a flue within 2 feet
d.
distance from the circuit breaker
 

 61. 

Which of the following could cause evaporator flooding on a capillary tube equipped system?
a.
low airflow through the evaporator
c.
excessive evaporator airflow
b.
low outdoor ambient
d.
high indoor load
 

 62. 

In the cooling mode of piston equipped heatpumps, the outdoor piston will be in the:
a.
bypass position
c.
metering position
b.
front-seated position
d.
vertical position
 

 63. 

The indoor coil frosts on start up of a new air-conditioner. Which of the following could be the cause?
a.
overcharge
c.
low indoor airflow
b.
restricted suction drier
d.
excessive indoor airflow
 

 64. 

On a call for cooling, with 230VAC supplied, T1 and L1 close, T2 and L2 do not make contact. What voltage readings would you get?
a.
230VAC between T1 & L1
c.
230VAC between L1 & L2
b.
230VAC between T2 & L2
d.
230VAC between R & C
 

 65. 

To determine proper heat anticipator settings, measure the current
a.
on the R wire
c.
on the C wire
b.
on the W wire
d.
on the G wire
 

 66. 

When checking compressor motor windings, the ohmmeter should be set on what scale?
a.
RX1
c.
RX1K
b.
RX100
d.
RX10K
 

 67. 

To remove non-condensable, connect the vacuum pump to
a.
both high and low sides
c.
high side only
b.
low side only
d.
suction only
 

 68. 

On start-up, a heatpump thermostat should be checked to see that
a.
first stage operates the compressor and second stage operates the reversing valve
c.
first stage operates the airhandler and second stage operates the compressor
b.
first stage operates the compressor and second stage operates the auxiliary heat
d.
first and second stage operate different stages of auxiliary heat
 

 69. 

The most accurate method of controlling refrigerant flow over a wide range of loads is to use
a.
a capillary tube
c.
use an automatic expansion valve
b.
use a thermostatic expansion valve
d.
use a metering orifice
 

 70. 

Which of the following could cause high discharge pressure in a cooling system?
a.
dirty condenser coil
c.
dirty evaporator coil
b.
low charge
d.
liquid line restriction
 

 71. 

Manufacturer's requirements for venting "90+" furnaces include, size of the vent, number of elbows, venting materials and
a.
distance to combustibles
c.
temperature rise
b.
length of vent
d.
direction of air flow
 

 72. 

The most important advantage of using higher silver content alloys when brazing is that
a.
the joint is stronger
c.
the joint will not corrode
b.
less heat is required
d.
flux is not required
 

 73. 

On a slit-system air-conditioner, increasing the evaporator airflow
a.
removes less humidity
c.
increases the temperature difference across the coil
b.
causes frost to build up on the coil
d.
removes more humidity
 

 74. 

Step opening gas valves are valves that open
a.
at a partial rate, then change to full rate
c.
at full rate then change to a partial rate
b.
and close at the same time intervals
d.
to one burner at a time
 

 75. 

Which of the following could indicate an overcharge on a fixed metering  air-conditioner?
a.
low head, low suction
c.
excessive superheat
b.
high head, high suction
d.
low sub-cooling
 

 76. 

What is the primary reason for a low ambient control?
a.
controls indoor blower during mild weather
c.
maintains minimum discharge pressure
b.
shuts off the compressor when outdoor temperature rises above 35F
d.
switches condenser fan to high speed
 

 77. 

Which of the following are needed to determine superheat?
a.
discharge line temperature and suction line temperature
c.
liquid pressure and temperature
b.
air temperature difference across evaporator
d.
suction pressure and temperature
 

 78. 

On a service call to an oil furnace, what safety precaution should the technician make before firing the furnace?
a.
disconnect electricity
c.
check oil pressure
b.
check for grounded electrodes
d.
check for liquid oil in the combustion chamber
 

 79. 

Which of the following are needed to check oil furnace efficiency?
a.
net stack temperature and CO2 concentration
c.
net stack and indoor temperature
b.
net stack temperature and CO
d.
stack temperature and fuel pressure
 

 80. 

When using hard drawn tubing, which of the following should be used to fabricate a 90 bend?
a.
a 90 flared union
c.
a spring bender
b.
a 90 compression elbow
d.
a long radius 90 elbow
 

 81. 

What is the maximum fill level for a refrigerant recovery cylinder?
a.
50% of name plate capacity
c.
70% of rated capacity
b.
60% of name plate
d.
80% of rated capacity
 

 82. 

If the pressure switch on an induced draft furnace fails to close, the most likely cause is
a.
a blockage in the vent system
c.
manifold pressure too low
b.
circulating blower is on the wrong speed
d.
manifold pressure too high
 

 83. 

To energize the electric strips in a heatpump the technician may need to
a.
check the anticipator current
c.
jumper or adjust outdoor thermostats
b.
turn thermostat all of the way down
d.
check auxiliary heat light on thermostat
 

 84. 

Lower than normal voltage at the compressor contactor coil can be caused by
a.
thermostat wire too small
c.
higher that normal supply voltage
b.
oversized control transformer
d.
incorrect capacitor
 

 85. 

When check flame current, the meter should be set for
a.
AC milliamps
c.
AC microamps
b.
DC milliamps
d.
DC microamps
 

 86. 

The common terminal on heatpump thermostats is used for
a.
power the outdoor  thermostats
c.
stabilize the voltage in the cooling cycle
b.
power shunt type anticipator and indicator lights
d.
add power to the back-up heaters
 

 87. 

The vent safety switch installed in the draft hood area
a.
protects the furnace from overheating if the limit fails
c.
shuts down the gas valve if the furnace is spilling vent products
b.
automatically increases blower speed if the furnace overheats
d.
protects the heat exchanger from damage
 

 88. 

For safety, when checking an electric furnace, after turning off the unit disconnect you should check
a.
ohms from L1 to ground
c.
resistance of the sequencers
b.
voltage on the line side of the disconnect
d.
voltage on the load side of the disconnect
 

 89. 

Velocity in a 12" X 12" duct is measured at 800 FM.hat is the air volume?
a.
144 CFM
c.
800 CFM
b.
400 CFM
d.
1600 CFM
 

 90. 

Refrigerants can become toxic when they contact
a.
contaminated oil
c.
a high heat source
b.
water or moisture
d.
nitrogen
 

 91. 

Velocity pressure is static pressure minus total pressure
a.
total pressure minus static pressure
c.
static pressure plus total pressure
b.
static pressure minus differential pressure
d.
static pressure times duct cross sectional area
 

 92. 

Manifold gas pressure on a single stage propane system should normally be
a.
3.5" wc
c.
10" wc
b.
7" wc
d.
13" wc
 

 93. 

Which of the following is not an accepted method of leak detection?
a.
R-22 and compressed air
c.
R-22 and nitrogen
b.
R-22 and an inert gas
d.
nitrogen only
 

 94. 

The purpose of the National Fuel Gas Code is to
a.
provide a material list for a gas installation
c.
provide minimum safety requirements for a gas appliance/installation
b.
identify the number of safety devices needed in a gas installation
d.
satisfy the local building code
 

 95. 

What happens to static pressure after sealing a leaky duct system?
a.
increases
c.
changes to total pressure
b.
decreases
d.
changes to velocity pressure
 

 96. 

What instrument is used to measure duct velocity
a.
pyrometer
c.
hygrometer
b.
anemometer
d.
tachometer
 

 97. 

What is the biggest disadvantage of using flex duct as compared to sheetmetal duct?
a.
less pressure drop
c.
more restriction
b.
more fittings required
d.
increased installation time
 

 98. 

Partially restricting the return side of a duct system will cause the amperage of a PSC blower to
a.
decrease
c.
increase
b.
stay the same
d.
hunt up and down
 

 99. 

What is the biggest safety hazard when using A1 refrigerants
a.
they are poisonous
c.
they are lighter than air
b.
suffocation
d.
they ignite in air
 

 100. 

A refrigerant cylinder weighs 36 lbs. The cylinder alone weighs 6 lbs. A technician uses 1/6 of the refrigerant on one unit. He then uses 10 lbs on another job. How much refrigerant is left in the cylinder?
a.
14 lbs
c.
16 lbs
b.
15 lbs
d.
20 lbs
 



 
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