UTAH PLUMBING CODE EXAM – QUESTIONS AND ANSWERS | VERIFIED AND WELL
DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
*Core Domains*
*- Administration and Enforcement*
*- General Regulations and Fixtures*
*- Water Heaters and Storage Tanks*
*- Water Supply and Distribution*
*- Sanitary Drainage Systems*
*- Vents and Venting Systems*
*- Storm Drainage and Special Piping*
*- Gray Water Recycling Systems*
*- Licensing and Professional Ethics*
*Introduction*
*The purpose of this comprehensive assessment is to evaluate the competency and
readiness of candidates seeking licensure under the Utah Plumbing Code. This exam
assesses fundamental knowledge of hydraulic principles, materials, and installation
methods, alongside strict adherence to state amendments and safety regulations. The
structure consists of multiple-choice and scenario-based questions designed to mirror real-
world challenges faced by plumbing professionals. Candidates must demonstrate proficiency
in technical calculations, code compliance, and ethical decision-making. By focusing on
critical thinking and the application of regulatory standards, this exam ensures that
practitioners possess the skills necessary to protect public health and safety through reliable
plumbing systems.*
SECTION ONE: QUESTIONS 1–100
1. What is the minimum required size for a building sewer in a residential application
under the Utah Plumbing Code?
A. 2 inches B. 3 inches C. 4 inches D. 6 inches
B. 3 inches
Explanation: While 4 inches is common practice, the code allows a minimum of 3 inches
for building sewers, provided the fixture unit load does not exceed the capacity of the pipe.
2. A plumbing permit is generally required for which of the following activities?
,A. Stopping of leaks in drains or pipes B. Clearing of stoppages C. Replacement of a water
heater D. Replacement of a faucet washer
C. Replacement of a water heater
Explanation: The replacement of water heaters involves fuel gas or high-voltage
electrical connections and pressure vessels, necessitating a permit and inspection, unlike
minor repairs.
3. What is the minimum clearance required in front of a water closet to any wall,
fixture, or door?
A. 15 inches B. 18 inches C. 21 inches D. 24 inches
C. 21 inches
Explanation: To ensure adequate user space and accessibility, the code mandates a
minimum of 21 inches of clear space in front of the water closet.
4. Which of the following materials is prohibited for use in underground water
distribution piping?
A. Type K copper B. PEX tubing C. Galvanized steel pipe D. CPVC pipe
C. Galvanized steel pipe
Explanation: Galvanized steel pipe is prohibited for underground use due to its
susceptibility to corrosion and relatively short lifespan in soil.
5. What is the maximum distance a water heater temperature and pressure (T&P) relief
valve discharge pipe can terminate above the floor?
A. 2 inches B. 6 inches C. 12 inches D. 18 inches
B. 6 inches
Explanation: The discharge pipe must terminate between 1 inch and 6 inches above the
floor or waste receptor to prevent splashing while remaining visible.
6. A horizontal drainage pipe has a diameter of 3 inches. What is the minimum required
slope per foot?
A. 1/8 inch B. 1/4 inch C. 1/2 inch D. 1 inch
B. 1/4 inch
Explanation: For pipes 3 inches or smaller, the minimum slope is 1/4 inch per foot to
maintain scouring velocity and prevent solids from settling.
7. Which device is required to prevent backflow in a hose bibb application?
,A. Double check valve B. Reduced pressure zone assembly C. Atmospheric vacuum breaker
D. Vacuum breaker integrated into the sillcock
D. Vacuum breaker integrated into the sillcock
Explanation: Hose bibbs must be protected by a vacuum breaker to prevent non-potable
water from being siphoned back into the potable water supply.
8. When testing a DWV system with water, what is the minimum height the water
column must reach above the highest point of the system?
A. 5 feet B. 10 feet C. 15 feet D. 20 feet
B. 10 feet
Explanation: A water test requires a 10-foot head of water to provide sufficient pressure
to identify leaks in joints and fittings.
9. What is the maximum temperature allowed for water discharged into a public sewer
system?
A. 120 degrees F B. 140 degrees F C. 160 degrees F D. 180 degrees F
B. 140 degrees F
Explanation: Discharging water hotter than 140 degrees F can damage PVC piping and
disrupt the biological processes in sewage treatment.
10. A vent stack must extend at least how many inches above the roof line?
A. 6 inches B. 10 inches C. 12 inches D. 24 inches
A. 6 inches
Explanation: Vents must terminate at least 6 inches above the roof to prevent blockages
from snow or debris and ensure proper atmospheric pressure.
11. What is the minimum size of a trap for a residential kitchen sink?
A. 1-1/4 inches B. 1-1/2 inches C. 2 inches D. 3 inches
B. 1-1/2 inches
Explanation: The standard minimum trap size for a kitchen sink is 1-1/2 inches to
accommodate the expected flow rate and food waste.
12. In a scenario where a plumber discovers an immediate life-safety hazard in a client's
home, what is the most ethical first action?
, A. Finish the scheduled job and leave a note B. Inform the client and shut off the affected
utility if possible C. Call the building department before speaking to the client D. Ignore it if it
was not part of the original work order
B. Inform the client and shut off the affected utility if possible
Explanation: Professional ethics and safety standards require the plumber to mitigate
immediate hazards and ensure the occupant is informed.
13. Which of the following is considered a "critical" cross-connection?
A. A landscape irrigation system B. A fire sprinkler system without chemicals C. A carbonated
beverage dispenser D. A residential kitchen faucet
C. A carbonated beverage dispenser
Explanation: Carbonators require specialized backflow prevention (like a vented double
check valve) because CO2 reacting with copper piping can cause copper poisoning.
14. What is the minimum diameter for a building's main vent?
A. 1-1/2 inches B. 2 inches C. 3 inches D. Half the diameter of the building drain
D. Half the diameter of the building drain
Explanation: The aggregate area of vents must be at least half the diameter of the
building drain, but never less than 1-1/2 inches.
15. What is the maximum spacing for horizontal support of PVC piping?
A. 2 feet B. 4 feet C. 6 feet D. 10 feet
B. 4 feet
Explanation: PVC is a flexible material and requires support every 4 feet to prevent
sagging, which could lead to improper drainage slopes.
16. A pressure reducing valve (PRV) is required if the static water pressure at the building
entrance exceeds:
A. 60 psi B. 80 psi C. 100 psi D. 125 psi
B. 80 psi
Explanation: High water pressure can damage fixtures and appliances; therefore, a PRV
is mandated when pressure exceeds 80 psi.
17. Which type of joint is generally prohibited for use in a drainage system?
A. Solvent weld B. Hubless coupling C. Solder joint D. Mastic or putty joint
DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
*Core Domains*
*- Administration and Enforcement*
*- General Regulations and Fixtures*
*- Water Heaters and Storage Tanks*
*- Water Supply and Distribution*
*- Sanitary Drainage Systems*
*- Vents and Venting Systems*
*- Storm Drainage and Special Piping*
*- Gray Water Recycling Systems*
*- Licensing and Professional Ethics*
*Introduction*
*The purpose of this comprehensive assessment is to evaluate the competency and
readiness of candidates seeking licensure under the Utah Plumbing Code. This exam
assesses fundamental knowledge of hydraulic principles, materials, and installation
methods, alongside strict adherence to state amendments and safety regulations. The
structure consists of multiple-choice and scenario-based questions designed to mirror real-
world challenges faced by plumbing professionals. Candidates must demonstrate proficiency
in technical calculations, code compliance, and ethical decision-making. By focusing on
critical thinking and the application of regulatory standards, this exam ensures that
practitioners possess the skills necessary to protect public health and safety through reliable
plumbing systems.*
SECTION ONE: QUESTIONS 1–100
1. What is the minimum required size for a building sewer in a residential application
under the Utah Plumbing Code?
A. 2 inches B. 3 inches C. 4 inches D. 6 inches
B. 3 inches
Explanation: While 4 inches is common practice, the code allows a minimum of 3 inches
for building sewers, provided the fixture unit load does not exceed the capacity of the pipe.
2. A plumbing permit is generally required for which of the following activities?
,A. Stopping of leaks in drains or pipes B. Clearing of stoppages C. Replacement of a water
heater D. Replacement of a faucet washer
C. Replacement of a water heater
Explanation: The replacement of water heaters involves fuel gas or high-voltage
electrical connections and pressure vessels, necessitating a permit and inspection, unlike
minor repairs.
3. What is the minimum clearance required in front of a water closet to any wall,
fixture, or door?
A. 15 inches B. 18 inches C. 21 inches D. 24 inches
C. 21 inches
Explanation: To ensure adequate user space and accessibility, the code mandates a
minimum of 21 inches of clear space in front of the water closet.
4. Which of the following materials is prohibited for use in underground water
distribution piping?
A. Type K copper B. PEX tubing C. Galvanized steel pipe D. CPVC pipe
C. Galvanized steel pipe
Explanation: Galvanized steel pipe is prohibited for underground use due to its
susceptibility to corrosion and relatively short lifespan in soil.
5. What is the maximum distance a water heater temperature and pressure (T&P) relief
valve discharge pipe can terminate above the floor?
A. 2 inches B. 6 inches C. 12 inches D. 18 inches
B. 6 inches
Explanation: The discharge pipe must terminate between 1 inch and 6 inches above the
floor or waste receptor to prevent splashing while remaining visible.
6. A horizontal drainage pipe has a diameter of 3 inches. What is the minimum required
slope per foot?
A. 1/8 inch B. 1/4 inch C. 1/2 inch D. 1 inch
B. 1/4 inch
Explanation: For pipes 3 inches or smaller, the minimum slope is 1/4 inch per foot to
maintain scouring velocity and prevent solids from settling.
7. Which device is required to prevent backflow in a hose bibb application?
,A. Double check valve B. Reduced pressure zone assembly C. Atmospheric vacuum breaker
D. Vacuum breaker integrated into the sillcock
D. Vacuum breaker integrated into the sillcock
Explanation: Hose bibbs must be protected by a vacuum breaker to prevent non-potable
water from being siphoned back into the potable water supply.
8. When testing a DWV system with water, what is the minimum height the water
column must reach above the highest point of the system?
A. 5 feet B. 10 feet C. 15 feet D. 20 feet
B. 10 feet
Explanation: A water test requires a 10-foot head of water to provide sufficient pressure
to identify leaks in joints and fittings.
9. What is the maximum temperature allowed for water discharged into a public sewer
system?
A. 120 degrees F B. 140 degrees F C. 160 degrees F D. 180 degrees F
B. 140 degrees F
Explanation: Discharging water hotter than 140 degrees F can damage PVC piping and
disrupt the biological processes in sewage treatment.
10. A vent stack must extend at least how many inches above the roof line?
A. 6 inches B. 10 inches C. 12 inches D. 24 inches
A. 6 inches
Explanation: Vents must terminate at least 6 inches above the roof to prevent blockages
from snow or debris and ensure proper atmospheric pressure.
11. What is the minimum size of a trap for a residential kitchen sink?
A. 1-1/4 inches B. 1-1/2 inches C. 2 inches D. 3 inches
B. 1-1/2 inches
Explanation: The standard minimum trap size for a kitchen sink is 1-1/2 inches to
accommodate the expected flow rate and food waste.
12. In a scenario where a plumber discovers an immediate life-safety hazard in a client's
home, what is the most ethical first action?
, A. Finish the scheduled job and leave a note B. Inform the client and shut off the affected
utility if possible C. Call the building department before speaking to the client D. Ignore it if it
was not part of the original work order
B. Inform the client and shut off the affected utility if possible
Explanation: Professional ethics and safety standards require the plumber to mitigate
immediate hazards and ensure the occupant is informed.
13. Which of the following is considered a "critical" cross-connection?
A. A landscape irrigation system B. A fire sprinkler system without chemicals C. A carbonated
beverage dispenser D. A residential kitchen faucet
C. A carbonated beverage dispenser
Explanation: Carbonators require specialized backflow prevention (like a vented double
check valve) because CO2 reacting with copper piping can cause copper poisoning.
14. What is the minimum diameter for a building's main vent?
A. 1-1/2 inches B. 2 inches C. 3 inches D. Half the diameter of the building drain
D. Half the diameter of the building drain
Explanation: The aggregate area of vents must be at least half the diameter of the
building drain, but never less than 1-1/2 inches.
15. What is the maximum spacing for horizontal support of PVC piping?
A. 2 feet B. 4 feet C. 6 feet D. 10 feet
B. 4 feet
Explanation: PVC is a flexible material and requires support every 4 feet to prevent
sagging, which could lead to improper drainage slopes.
16. A pressure reducing valve (PRV) is required if the static water pressure at the building
entrance exceeds:
A. 60 psi B. 80 psi C. 100 psi D. 125 psi
B. 80 psi
Explanation: High water pressure can damage fixtures and appliances; therefore, a PRV
is mandated when pressure exceeds 80 psi.
17. Which type of joint is generally prohibited for use in a drainage system?
A. Solvent weld B. Hubless coupling C. Solder joint D. Mastic or putty joint
