Plumbing Water Supply Systems 2

Question 1

What is the purpose of a tempering valve (mixing valve) on a water heater?

Accepted Answer

To blend hot and cold water to deliver water at a safe temperature

Answer

A tempering valve blends hot and cold water to deliver water at a pre-set safe temperature (typically 120°F) to prevent scalding.

Question 2

What is cross-connection in a plumbing system?

Accepted Answer

A physical link between potable water and a non-potable source

Answer

A cross-connection is any physical connection between potable (drinking) water and a non-potable source that could allow contamination of the drinking water supply.

Question 3

What is the recommended setting for a residential water heater thermostat to balance energy efficiency and safety?

Accepted Answer

120°F

Answer

120°F (49°C) is the EPA-recommended setting that balances energy efficiency, Legionella prevention, and scald protection for most households.

Question 4

What is the function of the anode rod in a tank-type water heater?

Accepted Answer

To sacrifice itself to corrosion, protecting the tank lining

Answer

The anode rod (sacrificial anode) is made of magnesium or aluminum and corrodes preferentially to protect the steel tank lining from rust.

Question 5

What does a pressure and temperature (P&T) relief valve on a water heater do?

Accepted Answer

Automatically releases water if pressure or temperature exceeds safe limits

Answer

The P&T relief valve is a critical safety device that automatically opens to release water and pressure if the tank exceeds safe temperature (210°F) or pressure (150 psi) limits.

Plumbing Practice Test

Plumbing Practice Test

Plumbing Water Supply Systems 2