TROUBLESHOOTING FINAL
REVIEW CORRECT QUESTIONS &
ANSWERS(RATED A+)
With the system operating, a technician gets a reading of 20 volts between the L1 and
T1 terminals at the contacts of the contactor. This tells the technician that: - ANSWER
The contacts are defective because they have a measurable voltage drop.
Why should caution be exercised when replacing a low efficiency air filter with a higher
efficiency air filter? - ANSWER Higher efficiency filters have a higher pressure drop that
can cause poor airflow.
As an operational safety check, what should be checked in the combustion gases for
combustion appliances? - ANSWER carbon monoxide levels
How does scheduling maintenance save time and money? - ANSWER It prevents small
problems from becoming big ones.
The phases of a planned maintenance service call are: - ANSWER Routine
maintenance, pre-start inspection, operational checks, and troubleshooting.
How will an extremely dirty air filter affect the amp draw of a PSC centrifugal blower
motor? - ANSWER It will cause the motor current to decrease because the fan will be
moving less air.
Before starting the unit: - ANSWER Check the power supply with the unit off.
After any repair or part replacement, the most important thing you must do is: -
ANSWER Recheck the system to be sure the concern has been resolved.
What color should the flames be in a correctly adjusted gas burner? - ANSWER Bright
blue inner cone with darker outer cone
Of the four phases listed below, which one is only performed on an "as needed" basis? -
ANSWER troubleshooting
A common cause of low system superheat is: - ANSWER Poor airflow across the
evaporator
The most important thing to know about a system before an operational check is: -
ANSWER How it should function
, As an operational safety check, the equipment rooms for combustion appliances should
be checked for high: - ANSWER carbon monoxide levels
A technician notes that an operating air conditioning system has ice formed on the
suction line at the condensing unit. The technician can reasonably assume that: -
ANSWER the evaporator coil is also frozen over
What side of an air conditioning coil generally collects dirt? - ANSWER the side where
air enters the coil
Why is planned maintenance often performed during the off-season? - ANSWER most
equipment fails during the off season
The most common times to perform a seasonal check on heating equipment is in the: -
ANSWER fall
How does performing planned maintenance save the customer money? - ANSWER
Reduced operational cost and longer equipment life
Before starting to change a belt on a belt drive blower, the technician should: -
ANSWER Turn the power to the unit off and lock it out.
How is a temperature-pressure relief valve on a hot-water boiler tested? - ANSWER Pull
lever and look for water at outlet of discharge pipe.
A problem that can look like low refrigerant charge if a service technician is only looking
at system pressures is - ANSWER low evaporator airflow
A system with an inefficient compressor will operate with - ANSWER A high suction
pressure and a low head pressure
Technicians that use a systems approach to troubleshooting - ANSWER must
understand the inter-relationship between different system components
Which manufacturer-supplied reference would probably be the most helpful on a no
heat furnace in letting you know the pressure switch is open or failed to open? -
ANSWER the fault code reference list
Which manufacturer-supplied reference uses pass/fail tests to guide the technician to
the possible cause of system malfunction? - ANSWER the logic flowchart
When searching for the break in a circuit by hop scotching, the technician checks -
ANSWER The voltage at each switch in the circuit
REVIEW CORRECT QUESTIONS &
ANSWERS(RATED A+)
With the system operating, a technician gets a reading of 20 volts between the L1 and
T1 terminals at the contacts of the contactor. This tells the technician that: - ANSWER
The contacts are defective because they have a measurable voltage drop.
Why should caution be exercised when replacing a low efficiency air filter with a higher
efficiency air filter? - ANSWER Higher efficiency filters have a higher pressure drop that
can cause poor airflow.
As an operational safety check, what should be checked in the combustion gases for
combustion appliances? - ANSWER carbon monoxide levels
How does scheduling maintenance save time and money? - ANSWER It prevents small
problems from becoming big ones.
The phases of a planned maintenance service call are: - ANSWER Routine
maintenance, pre-start inspection, operational checks, and troubleshooting.
How will an extremely dirty air filter affect the amp draw of a PSC centrifugal blower
motor? - ANSWER It will cause the motor current to decrease because the fan will be
moving less air.
Before starting the unit: - ANSWER Check the power supply with the unit off.
After any repair or part replacement, the most important thing you must do is: -
ANSWER Recheck the system to be sure the concern has been resolved.
What color should the flames be in a correctly adjusted gas burner? - ANSWER Bright
blue inner cone with darker outer cone
Of the four phases listed below, which one is only performed on an "as needed" basis? -
ANSWER troubleshooting
A common cause of low system superheat is: - ANSWER Poor airflow across the
evaporator
The most important thing to know about a system before an operational check is: -
ANSWER How it should function
, As an operational safety check, the equipment rooms for combustion appliances should
be checked for high: - ANSWER carbon monoxide levels
A technician notes that an operating air conditioning system has ice formed on the
suction line at the condensing unit. The technician can reasonably assume that: -
ANSWER the evaporator coil is also frozen over
What side of an air conditioning coil generally collects dirt? - ANSWER the side where
air enters the coil
Why is planned maintenance often performed during the off-season? - ANSWER most
equipment fails during the off season
The most common times to perform a seasonal check on heating equipment is in the: -
ANSWER fall
How does performing planned maintenance save the customer money? - ANSWER
Reduced operational cost and longer equipment life
Before starting to change a belt on a belt drive blower, the technician should: -
ANSWER Turn the power to the unit off and lock it out.
How is a temperature-pressure relief valve on a hot-water boiler tested? - ANSWER Pull
lever and look for water at outlet of discharge pipe.
A problem that can look like low refrigerant charge if a service technician is only looking
at system pressures is - ANSWER low evaporator airflow
A system with an inefficient compressor will operate with - ANSWER A high suction
pressure and a low head pressure
Technicians that use a systems approach to troubleshooting - ANSWER must
understand the inter-relationship between different system components
Which manufacturer-supplied reference would probably be the most helpful on a no
heat furnace in letting you know the pressure switch is open or failed to open? -
ANSWER the fault code reference list
Which manufacturer-supplied reference uses pass/fail tests to guide the technician to
the possible cause of system malfunction? - ANSWER the logic flowchart
When searching for the break in a circuit by hop scotching, the technician checks -
ANSWER The voltage at each switch in the circuit
