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NATE Certified HVAC Professional (CHP-5)
Installation Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION
This Comprehensive set of multiple choice questions is designed for the NATE Certified
HVAC Professional (CHP-5) Installation Exam, a specialized certification assessment
administered by North American Technician Excellence (NATE). The exam evaluates a
technician's practical knowledge of installing residential heating, cooling, and heat
pump systems, concentrating on essential field tasks such as assembling and sealing
gas piping and plastic vent systems, safely handling and charging refrigerant,
mounting and leveling indoor and outdoor units, connecting electrical disconnects and
field wiring, and performing thorough start-up and checkout procedures—including
verifying correct airflow, condensate drainage, gas pressure, and voltage supply.
QUESTION 1
When cutting rigid metal gas pipe, which tool is required to ensure a clean, burr-free
edge before threading?
A. Hacksaw
B. Reciprocating saw
C. Pipe cutter with a sharp wheel
D. Angle grinder with a cutoff wheel
CORRECT ANSWER: C
EXPERT RATIONALE: A pipe cutter produces a square, clean cut without burrs, essential
for proper threading and leak-free joints. Hacksaws and power saws leave rough edges
that must be reamed.
QUESTION 2
What is the primary reason for applying pipe thread sealant only to the male threads of
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a gas pipe connection?
A. To prevent corrosion on the female fitting
B. To ensure sealant does not enter the gas stream and clog orifices
C. To allow easy disassembly later
D. To comply with electrical bonding requirements
CORRECT ANSWER: B
EXPERT RATIONALE: Sealant applied to male threads can be forced into the gas stream
if placed on female threads, potentially clogging burner orifices and control valves.
Male-thread application minimizes this risk.
QUESTION 3
When assembling schedule 40 PVC vent piping, after dry-fitting all components, what is
the proper next step before applying solvent cement?
A. Clean the pipe and fittings with water only
B. Apply PVC primer to both the pipe and fitting socket; do not allow primer to dry
completely before applying cement
C. Apply cement without primer to save time
D. Sand the pipe ends with 80-grit sandpaper
CORRECT ANSWER: B
EXPERT RATIONALE: PVC primer cleans and softens surfaces. Solvent cement must be
applied while primer is still wet to achieve a proper bond.
QUESTION 4
Which of the following is the correct procedure for terminating a 90%+ condensing
furnace’s PVC intake and exhaust pipes through a sidewall?
A. Both pipes must slope toward the outdoors
B. Exhaust pipe slopes toward the furnace, intake pipe slopes outdoors
C. Both pipes must slope back toward the furnace with a minimum 1/4 inch per foot
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D. Only the exhaust pipe needs to slope; intake can be level
CORRECT ANSWER: C
EXPERT RATIONALE: Condensate management requires both intake and exhaust pipes
to slope toward the furnace to drain condensation back to the unit. A typical slope is 1/4
inch per foot.
QUESTION 5
When installing a gas vent system using B-vent, the minimum clearance to combustibles
is typically:
A. 0 inches (contact permitted)
B. 1 inch
C. 6 inches
D. 12 inches
CORRECT ANSWER: B
EXPERT RATIONALE: Listed B-vent carries a 1-inch clearance to combustibles as tested
and required by code, unless the manufacturer specifies otherwise. Zero clearance is not
permitted.
QUESTION 6
What is the minimum required pressure test for a residential natural gas piping system
before appliance connection?
A. 3 psig for 10 minutes
B. 10 psig for 15 minutes
C. 1.5 times the maximum working pressure, but not less than 3 psig
D. 25 psig for 24 hours
CORRECT ANSWER: C
EXPERT RATIONALE: Code requires testing at 1.5 times the maximum operating pressure
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with a minimum of 3 psig for a duration of at least 10 minutes, using a manometer or
gauge.
QUESTION 7
A technician uses an electronic combustible gas detector to locate a leak on a
completed gas piping assembly. At which location is a leak most likely after threading
and tightening?
A. In the middle of a straight pipe run
B. At the union or threaded joint
C. Under the pipe hanger
D. At the gas shutoff valve body
CORRECT ANSWER: B
EXPERT RATIONALE: Threaded joints and unions are the most common leak points due
to imperfect sealing, cross-threading, or insufficient thread engagement.
QUESTION 8
When installing a condensing furnace, the PVC exhaust vent pipe must be supported
horizontally at intervals not exceeding:
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
CORRECT ANSWER: B
EXPERT RATIONALE: PVC piping schedule 40 typically requires horizontal support every
4 feet to prevent sagging and ensure proper slope. Check local code for variations.
QUESTION 9
Why should a technician avoid using an open flame to check for refrigerant leaks?
NATE Certified HVAC Professional (CHP-5)
Installation Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION
This Comprehensive set of multiple choice questions is designed for the NATE Certified
HVAC Professional (CHP-5) Installation Exam, a specialized certification assessment
administered by North American Technician Excellence (NATE). The exam evaluates a
technician's practical knowledge of installing residential heating, cooling, and heat
pump systems, concentrating on essential field tasks such as assembling and sealing
gas piping and plastic vent systems, safely handling and charging refrigerant,
mounting and leveling indoor and outdoor units, connecting electrical disconnects and
field wiring, and performing thorough start-up and checkout procedures—including
verifying correct airflow, condensate drainage, gas pressure, and voltage supply.
QUESTION 1
When cutting rigid metal gas pipe, which tool is required to ensure a clean, burr-free
edge before threading?
A. Hacksaw
B. Reciprocating saw
C. Pipe cutter with a sharp wheel
D. Angle grinder with a cutoff wheel
CORRECT ANSWER: C
EXPERT RATIONALE: A pipe cutter produces a square, clean cut without burrs, essential
for proper threading and leak-free joints. Hacksaws and power saws leave rough edges
that must be reamed.
QUESTION 2
What is the primary reason for applying pipe thread sealant only to the male threads of
,2|Page
a gas pipe connection?
A. To prevent corrosion on the female fitting
B. To ensure sealant does not enter the gas stream and clog orifices
C. To allow easy disassembly later
D. To comply with electrical bonding requirements
CORRECT ANSWER: B
EXPERT RATIONALE: Sealant applied to male threads can be forced into the gas stream
if placed on female threads, potentially clogging burner orifices and control valves.
Male-thread application minimizes this risk.
QUESTION 3
When assembling schedule 40 PVC vent piping, after dry-fitting all components, what is
the proper next step before applying solvent cement?
A. Clean the pipe and fittings with water only
B. Apply PVC primer to both the pipe and fitting socket; do not allow primer to dry
completely before applying cement
C. Apply cement without primer to save time
D. Sand the pipe ends with 80-grit sandpaper
CORRECT ANSWER: B
EXPERT RATIONALE: PVC primer cleans and softens surfaces. Solvent cement must be
applied while primer is still wet to achieve a proper bond.
QUESTION 4
Which of the following is the correct procedure for terminating a 90%+ condensing
furnace’s PVC intake and exhaust pipes through a sidewall?
A. Both pipes must slope toward the outdoors
B. Exhaust pipe slopes toward the furnace, intake pipe slopes outdoors
C. Both pipes must slope back toward the furnace with a minimum 1/4 inch per foot
,3|Page
D. Only the exhaust pipe needs to slope; intake can be level
CORRECT ANSWER: C
EXPERT RATIONALE: Condensate management requires both intake and exhaust pipes
to slope toward the furnace to drain condensation back to the unit. A typical slope is 1/4
inch per foot.
QUESTION 5
When installing a gas vent system using B-vent, the minimum clearance to combustibles
is typically:
A. 0 inches (contact permitted)
B. 1 inch
C. 6 inches
D. 12 inches
CORRECT ANSWER: B
EXPERT RATIONALE: Listed B-vent carries a 1-inch clearance to combustibles as tested
and required by code, unless the manufacturer specifies otherwise. Zero clearance is not
permitted.
QUESTION 6
What is the minimum required pressure test for a residential natural gas piping system
before appliance connection?
A. 3 psig for 10 minutes
B. 10 psig for 15 minutes
C. 1.5 times the maximum working pressure, but not less than 3 psig
D. 25 psig for 24 hours
CORRECT ANSWER: C
EXPERT RATIONALE: Code requires testing at 1.5 times the maximum operating pressure
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with a minimum of 3 psig for a duration of at least 10 minutes, using a manometer or
gauge.
QUESTION 7
A technician uses an electronic combustible gas detector to locate a leak on a
completed gas piping assembly. At which location is a leak most likely after threading
and tightening?
A. In the middle of a straight pipe run
B. At the union or threaded joint
C. Under the pipe hanger
D. At the gas shutoff valve body
CORRECT ANSWER: B
EXPERT RATIONALE: Threaded joints and unions are the most common leak points due
to imperfect sealing, cross-threading, or insufficient thread engagement.
QUESTION 8
When installing a condensing furnace, the PVC exhaust vent pipe must be supported
horizontally at intervals not exceeding:
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
CORRECT ANSWER: B
EXPERT RATIONALE: PVC piping schedule 40 typically requires horizontal support every
4 feet to prevent sagging and ensure proper slope. Check local code for variations.
QUESTION 9
Why should a technician avoid using an open flame to check for refrigerant leaks?
