Journeyman Plumbers Exam Plumbing Fixtures and Appliances 3 — Questions and Answers
Question 1: Which appliance requires a dedicated GFCI-protected circuit AND a plumbing drain connection?
- Gas range
- Dishwasher
- Garbage disposal
- Clothes washer (Correct answer)
Correct answer: Clothes washer
A clothes washer requires both a dedicated electrical circuit (with GFCI in some locations) and a standpipe drain connection for proper installation.
Question 2: The minimum standpipe height for a clothes washer drain receptor above the trap weir is:
- 12 inches
- 18 inches
- 24 inches (Correct answer)
- 36 inches
Correct answer: 24 inches
The IPC requires a standpipe receptor for clothes washers to extend a minimum of 24 inches above the trap weir to prevent backflow.
Question 3: A water heater temperature and pressure (T&P) relief valve discharge pipe must terminate:
- Into the cold water supply line
- At a floor drain or within 6 inches of the floor (Correct answer)
- Directly outside the building
- Into the hot water outlet pipe
Correct answer: At a floor drain or within 6 inches of the floor
The T&P relief valve discharge must terminate at a safe point of discharge, typically within 6 inches of the floor or into a floor drain, to prevent scalding.
Question 4: What is the purpose of the air gap on a dishwasher drain connection?
- To reduce water hammer
- To prevent backflow of contaminated water into the dishwasher (Correct answer)
- To allow venting of drain gases
- To regulate drain flow rate
Correct answer: To prevent backflow of contaminated water into the dishwasher
The air gap provides a physical break in the drain line to prevent contaminated sink or disposal water from siphoning back into the dishwasher.
Question 5: A garbage disposal should be connected to the drain system using:
- A 1-1/4 inch trap and drain
- A 1-1/2 inch trap and drain minimum (Correct answer)
- A 2-inch trap and drain minimum
- A 3-inch trap and drain
Correct answer: A 1-1/2 inch trap and drain minimum
Garbage disposals require a minimum 1-1/2 inch trap and drain connection to handle the ground food waste without clogging.
Question 6: Which type of water heater uses a heat exchanger coil submerged in a storage tank supplied by a boiler?
- Tankless water heater
- Heat pump water heater
- Indirect-fired water heater (Correct answer)
- Power-vent water heater
Correct answer: Indirect-fired water heater
An indirect-fired water heater uses a boiler to heat water circulated through a heat exchanger coil inside the storage tank rather than burning fuel directly.
Question 7: When a lavatory is installed in a wheelchair-accessible restroom, the drain trap and supply pipes must be:
- Concealed inside the wall with access panels
- Insulated to protect users from contact burns (Correct answer)
- Raised to the standard 21-inch rough-in height
- Installed with chrome-plated exposed pipes only
Correct answer: Insulated to protect users from contact burns
ADA-compliant accessible lavatories require insulated or covered drain and supply pipes to prevent burns to users with limited sensation who may contact the pipes.
