Journeyman Plumbers Exam Water Heaters and Hot Water Systems

Question 1

Where must a temperature and pressure (T&P) relief valve discharge pipe terminate?

Accepted Answer

Within 6 inches of the floor

Answer

Directly into a floor drain

Answer

At least 24 inches above the floor

Answer

Into the cold water supply line

Question 2

What is the purpose of the dip tube in a storage tank water heater?

Accepted Answer

To direct incoming cold water to the bottom of the tank

Answer

To drain sediment from the bottom of the tank

Answer

To measure the internal water temperature

Answer

To prevent backflow into the cold supply line

Question 3

What is the primary purpose of the sacrificial anode rod in a tank-type water heater?

Accepted Answer

To protect the steel tank lining from corrosion through galvanic action

Answer

To improve heating element efficiency

Answer

To filter sediment from the incoming water supply

Answer

To regulate internal water pressure

Question 4

What is the maximum water heater thermostat setting recommended by most US plumbing codes to prevent scalding in residential occupancies?

Accepted Answer

120°F (49°C)

Answer

140°F (60°C)

Answer

110°F (43°C)

Answer

130°F (54°C)

Question 5

At what minimum height above the garage floor must the ignition source of a gas water heater be located?

Accepted Answer

18 inches

Answer

12 inches

Answer

24 inches

Answer

36 inches

Question 6

What type of expansion tank is required when a pressure-reducing valve (PRV) or check valve creates a closed water system on the cold water supply?

Accepted Answer

Closed bladder-type thermal expansion tank

Answer

Open atmospheric expansion tank

Answer

In-line pressure relief canister

Answer

No expansion tank is required for closed systems

Question 7

What is the minimum diameter of the discharge pipe for a T&P relief valve on a residential storage water heater?

Accepted Answer

3/4 inch

Answer

1/2 inch

Answer

1 inch

Answer

3/8 inch