InterNACHI Exam Questions and
Answers 100% Pass
A condensate line should ______________.
a. empty directly into the waste drain line
b. end 1 inch above the waste drain line
c. not drain into the waste drain line
d. extend at least 1 inch into the waste drain line - CORRECT ANSWER-b. end 1
inch above the waste drain line
A condensing furnace _____________.
a. works like an air conditioner, except that it heats instead of cools
b. is a furnace covered in condensation
c. is more efficient than conventional furnaces and uses a secondary heat
exchanger - CORRECT ANSWER-c. is more efficient than conventional furnaces
and uses a secondary heat exchanger
A crawlspace should have one vent at least ______ feet from the corner.
a. 3
,b. 2
c. 4
d. 1-1/2 - CORRECT ANSWER-a. 3
A damaged or nicked wire is a safety hazard because the ___________________.
a. effective resistance of the wire is increased, so the fuse can no longer adequately
protect the wire from overheating
b. damaged wire may corrode
c. wire's effective diameter has been decreased, thereby decreasing the resistance of
the wire - CORRECT ANSWER-a. effective resistance of the wire is increased, so
the fuse can no longer adequately protect the wire from overheating
A dentil can be found on a _________.
a. dormer window
b. widow's walk
c. cornice
d. turret - CORRECT ANSWER-c. cornice
A drainpipe from a catch basin should be at least ____ inches in diameter.
a5
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,b4
c 2-1/2
d 3-1/2
e 3 - CORRECT ANSWER-e 3
A dryer vent with a 45- and 90-degree elbow should have a maximum length of
_____ feet.
a 17-1/2
b 16
c 14-1/2
d 10 - CORRECT ANSWER-a 17-1/2
A firewall with a 1-hour rating has a _____-inch minimum distance for metal
electrical outlet boxes installed on opposite sides of the wall.
a 30
b 36
c 24
d 18 - CORRECT ANSWER-c 24
A flex line connected to a gas heater may be _____ feet long.
a6
, b3
c9
d 12 - CORRECT ANSWER-b 3
A forced-air furnace ____________ describes an incorrect installation.
a with a work space having a width of less than 30 inches
b having a combustion chamber situated 6 inches from a door
c that is isolated from the bedroom or bathroom
d with return-air grilles situated at least 10 feet from combustibles - CORRECT
ANSWER-a with a work space having a width of less than 30 inches
A forced-air heating system that is fueled by oil is evidenced by the presence of a
___________.
a pressure-temperature gauge
b barometric damper
c condensate line
d sight glass - CORRECT ANSWER-b barometric damper
A foundation supporting wood framing should extend ___ inches above a finished
grade.
COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED
Answers 100% Pass
A condensate line should ______________.
a. empty directly into the waste drain line
b. end 1 inch above the waste drain line
c. not drain into the waste drain line
d. extend at least 1 inch into the waste drain line - CORRECT ANSWER-b. end 1
inch above the waste drain line
A condensing furnace _____________.
a. works like an air conditioner, except that it heats instead of cools
b. is a furnace covered in condensation
c. is more efficient than conventional furnaces and uses a secondary heat
exchanger - CORRECT ANSWER-c. is more efficient than conventional furnaces
and uses a secondary heat exchanger
A crawlspace should have one vent at least ______ feet from the corner.
a. 3
,b. 2
c. 4
d. 1-1/2 - CORRECT ANSWER-a. 3
A damaged or nicked wire is a safety hazard because the ___________________.
a. effective resistance of the wire is increased, so the fuse can no longer adequately
protect the wire from overheating
b. damaged wire may corrode
c. wire's effective diameter has been decreased, thereby decreasing the resistance of
the wire - CORRECT ANSWER-a. effective resistance of the wire is increased, so
the fuse can no longer adequately protect the wire from overheating
A dentil can be found on a _________.
a. dormer window
b. widow's walk
c. cornice
d. turret - CORRECT ANSWER-c. cornice
A drainpipe from a catch basin should be at least ____ inches in diameter.
a5
COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED
,b4
c 2-1/2
d 3-1/2
e 3 - CORRECT ANSWER-e 3
A dryer vent with a 45- and 90-degree elbow should have a maximum length of
_____ feet.
a 17-1/2
b 16
c 14-1/2
d 10 - CORRECT ANSWER-a 17-1/2
A firewall with a 1-hour rating has a _____-inch minimum distance for metal
electrical outlet boxes installed on opposite sides of the wall.
a 30
b 36
c 24
d 18 - CORRECT ANSWER-c 24
A flex line connected to a gas heater may be _____ feet long.
a6
, b3
c9
d 12 - CORRECT ANSWER-b 3
A forced-air furnace ____________ describes an incorrect installation.
a with a work space having a width of less than 30 inches
b having a combustion chamber situated 6 inches from a door
c that is isolated from the bedroom or bathroom
d with return-air grilles situated at least 10 feet from combustibles - CORRECT
ANSWER-a with a work space having a width of less than 30 inches
A forced-air heating system that is fueled by oil is evidenced by the presence of a
___________.
a pressure-temperature gauge
b barometric damper
c condensate line
d sight glass - CORRECT ANSWER-b barometric damper
A foundation supporting wood framing should extend ___ inches above a finished
grade.
COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED
