Journeyman Plumbers Exam Water Heaters and Hot Water Systems 2

Question 1

At what minimum storage temperature is Legionella bacteria effectively inhibited in a hot water system?

Accepted Answer

140°F (60°C)

Answer

120°F (49°C)

Answer

130°F (54°C)

Answer

110°F (43°C)

Question 2

What does the 'first-hour rating' (FHR) indicate about a storage water heater?

Accepted Answer

The total gallons of hot water the unit can deliver in the first hour starting with a full tank

Answer

The time required to heat a full tank of cold water from 40°F to 120°F

Answer

The unit's energy efficiency during the first hour of daily operation

Answer

The minimum warranty period required by federal law

Question 3

Which type of water heater venting uses a concentric pipe system to draw combustion air from outside while exhausting combustion gases directly outdoors?

Accepted Answer

Direct vent (sealed combustion)

Answer

Type B natural draft venting

Answer

Atmospheric venting with draft hood

Answer

Power vent with induced draft blower

Question 4

What is the maximum hot water delivery temperature typically permitted at fixtures in healthcare facilities and nursing homes?

Accepted Answer

110°F

Answer

120°F

Answer

105°F

Answer

115°F

Question 5

An atmospheric gas water heater is installed in a confined mechanical room. What is required to ensure safe operation?

Accepted Answer

A dedicated combustion air supply to the confined space

Answer

A carbon monoxide detector only

Answer

An exhaust fan rated for continuous duty

Answer

No additional provisions if the room has a door

Question 6

What is the minimum required diameter of a drain line from a water heater drain pan per most US plumbing codes?

Accepted Answer

3/4 inch

Answer

1/2 inch

Answer

1 inch

Answer

1-1/4 inch

Question 7

In which seismic design categories are water heaters typically required to be anchored or strapped to prevent overturning during an earthquake?

Accepted Answer

Seismic Design Categories C, D, E, and F (high seismic risk areas)

Answer

All categories nationwide, regardless of seismic risk

Answer

Only in coastal flood zones

Answer

Only where local jurisdictions adopt special ordinances