GAS CFESA PRACTICE TEST WITH VERIFIED
WITH VERIFIED QUESTIONS AND ANSWERS||
GUARANTEED PASS || ALREADY GRADED A+ ||
LATEST VERSION 2025
How do you adjust the bypass flame on a FD series thermostat? - ANSWER-
same as setting a bypass flame for a BJ thermostat, the bypass adjustment screw
marked "B" is on the front of the thermostat
Does the bypass flame ever go out on an FD thermostat if the flame is properly
adjusted? Why or why not? - ANSWER-Yes, on an FDO or FDH thermostat. If
the equipment has reached operating temperature and the thermostat knob is
turned down manually, eventually the bypass will go off to allow the equipment
to cool down
How do you correct a loose thermostat shaft problem on a FD series thermostat?
- ANSWER-turn the thermostat all the way down and mark the plate and the
thermostat body with the lining marks. then remove the two adjustment screws.
remove the shaft and the cup-shaped plate. Flatten the center of cup shaped
plate. reassemble the cup-shaped plate and the shaft properly, realigning the
components with the marks on the thermostat body. recalibrate the thermostat.
Exactly how do you calibrate a FD thermostat? - ANSWER-first check the
calibration of the bypass flame. check the equipment operating temperature with
a thermometer. if the calibration id off from the knob, loosen the two
adjustment screws and turn the shaft plate. retighten the screws, and reinstall the
knob. if the adjustment is still off, repeat the procedure.
,How do you know when you have to replace a BJ or FD thermostat? -
ANSWER-when they will not control the temperature or will not maintain
adjustment
What are the two functions of the primary air on an infrared burner? -
ANSWER-support the combustion and cool the burner box
What color should the surface of an infrared burner be? - ANSWER-Bright
orange or red
What does a blue colored flame indicate on an infrared burner? - ANSWER-
either too much or too little primary air
Why is gas pressure so important for impingement target burners? - ANSWER-
if gas pressure is too low, the flames burn at the bracket rather than at the target
What happens as you increase the flame size on a non-aerated pilot burner? -
ANSWER-the flames lift off the burner
Describe the proper flame for an aerated pilot burner - ANSWER-the flame will
be clear, blue, and well defined
Can pilot burners wear out? If so, how will you know when one is worn out? -
ANSWER-Yes, you will know they are worn out when you cannot get a clean,
blue, well defined flame
How will the burner flame appear if the orifice is not properly aligned? -
ANSWER-yellow flame
What is the function of a spoiler screw? - ANSWER-To help mix the gas and
air on short venturi burners.
, Why do steel burners corrode prematurely? - ANSWER-Heat corrosion from
overheating of the burners
Why is clean combustion air needed for infrared burners? - ANSWER-
contamination and dirt in the air can block the small holes in the tile
Why are low NOX burners becoming so popular? - ANSWER-requirements for
reducing pollution
What is necessary to create a low NOX burner? - ANSWER-The temperature of
the flame needs to be reduced.
What is the correct procedure for adjusting a bypass flame on a BJ thermostat? -
ANSWER-turn the thermostat to approx. 300 degrees and let the unit run for ten
minutes. Slowly turn the temperature down, and the flame should start to
modulate down. when it gets to the position where the flame remains the same
when you continue to turn it, that is the bypass flame. using the bypass
adjustment screw, adjust this flame to the smallest flame that will keep the
burner entirely lit
What is the exact procedure for recalibrating a BJ thermostat? - ANSWER-
place a thermometer over the top of the sensor bulb for the thermostat. check to
ensure the bypass flame is correctly set. record the temp when the burner
reaches the bypass flame. pop the center out of the thermostat knob. if the
calibration is off, insert a screw driver into the adjustment screw, holding it still,
and turn the knob until it reads the correct temp.
What does a throttiling thermostat refer to? - ANSWER-it refers to the fact that
the flame reduces as the temperature gets closer to the set point
Where is bypass adjustment located on a BJ thermostat? - ANSWER-on the
front of the thermostat body
WITH VERIFIED QUESTIONS AND ANSWERS||
GUARANTEED PASS || ALREADY GRADED A+ ||
LATEST VERSION 2025
How do you adjust the bypass flame on a FD series thermostat? - ANSWER-
same as setting a bypass flame for a BJ thermostat, the bypass adjustment screw
marked "B" is on the front of the thermostat
Does the bypass flame ever go out on an FD thermostat if the flame is properly
adjusted? Why or why not? - ANSWER-Yes, on an FDO or FDH thermostat. If
the equipment has reached operating temperature and the thermostat knob is
turned down manually, eventually the bypass will go off to allow the equipment
to cool down
How do you correct a loose thermostat shaft problem on a FD series thermostat?
- ANSWER-turn the thermostat all the way down and mark the plate and the
thermostat body with the lining marks. then remove the two adjustment screws.
remove the shaft and the cup-shaped plate. Flatten the center of cup shaped
plate. reassemble the cup-shaped plate and the shaft properly, realigning the
components with the marks on the thermostat body. recalibrate the thermostat.
Exactly how do you calibrate a FD thermostat? - ANSWER-first check the
calibration of the bypass flame. check the equipment operating temperature with
a thermometer. if the calibration id off from the knob, loosen the two
adjustment screws and turn the shaft plate. retighten the screws, and reinstall the
knob. if the adjustment is still off, repeat the procedure.
,How do you know when you have to replace a BJ or FD thermostat? -
ANSWER-when they will not control the temperature or will not maintain
adjustment
What are the two functions of the primary air on an infrared burner? -
ANSWER-support the combustion and cool the burner box
What color should the surface of an infrared burner be? - ANSWER-Bright
orange or red
What does a blue colored flame indicate on an infrared burner? - ANSWER-
either too much or too little primary air
Why is gas pressure so important for impingement target burners? - ANSWER-
if gas pressure is too low, the flames burn at the bracket rather than at the target
What happens as you increase the flame size on a non-aerated pilot burner? -
ANSWER-the flames lift off the burner
Describe the proper flame for an aerated pilot burner - ANSWER-the flame will
be clear, blue, and well defined
Can pilot burners wear out? If so, how will you know when one is worn out? -
ANSWER-Yes, you will know they are worn out when you cannot get a clean,
blue, well defined flame
How will the burner flame appear if the orifice is not properly aligned? -
ANSWER-yellow flame
What is the function of a spoiler screw? - ANSWER-To help mix the gas and
air on short venturi burners.
, Why do steel burners corrode prematurely? - ANSWER-Heat corrosion from
overheating of the burners
Why is clean combustion air needed for infrared burners? - ANSWER-
contamination and dirt in the air can block the small holes in the tile
Why are low NOX burners becoming so popular? - ANSWER-requirements for
reducing pollution
What is necessary to create a low NOX burner? - ANSWER-The temperature of
the flame needs to be reduced.
What is the correct procedure for adjusting a bypass flame on a BJ thermostat? -
ANSWER-turn the thermostat to approx. 300 degrees and let the unit run for ten
minutes. Slowly turn the temperature down, and the flame should start to
modulate down. when it gets to the position where the flame remains the same
when you continue to turn it, that is the bypass flame. using the bypass
adjustment screw, adjust this flame to the smallest flame that will keep the
burner entirely lit
What is the exact procedure for recalibrating a BJ thermostat? - ANSWER-
place a thermometer over the top of the sensor bulb for the thermostat. check to
ensure the bypass flame is correctly set. record the temp when the burner
reaches the bypass flame. pop the center out of the thermostat knob. if the
calibration is off, insert a screw driver into the adjustment screw, holding it still,
and turn the knob until it reads the correct temp.
What does a throttiling thermostat refer to? - ANSWER-it refers to the fact that
the flame reduces as the temperature gets closer to the set point
Where is bypass adjustment located on a BJ thermostat? - ANSWER-on the
front of the thermostat body
