CWS Installation, Maintenance & Troubleshooting 3

Question 1

When sizing a water softener for a household, which factor is NOT required for the calculation?

Accepted Answer

The color of the inlet plumbing

Answer

Softener sizing requires daily flow demand and hardness level to calculate daily grain removal need; plumbing color has no bearing on capacity calculations.

Question 2

A technician notices that a water softener is drawing brine but not rinsing properly, leaving salty water at the tap. What is the most likely component to inspect first?

Accepted Answer

The brine injector (venturi) and screen

Answer

A fouled injector or clogged screen restricts the rinse water flow, preventing complete removal of brine from the resin bed.

Question 3

What is the recommended practice when connecting a water treatment device to copper plumbing using a dielectric union?

Accepted Answer

Install the dielectric union to prevent galvanic corrosion between dissimilar metals

Answer

Dielectric unions contain an insulating liner that separates dissimilar metals, preventing galvanic corrosion that would otherwise degrade the connection over time.

Question 4

An iron filter using air injection shows rust-colored water at the tap after regeneration. What adjustment is most appropriate?

Accepted Answer

Extend the backwash duration

Answer

Extending the backwash duration allows more time to flush oxidized iron particles from the media bed, preventing carryover into the service line.

Question 5

Which of the following is the correct sequence for sanitizing a newly installed reverse osmosis system before placing it into service?

Accepted Answer

Add NSF-approved sanitizer, let soak, flush thoroughly until no sanitizer is detected

Answer

NSF-approved sanitizer is introduced, allowed to contact all surfaces for the recommended contact time, then thoroughly flushed until no residual sanitizer remains.

(CWS) Certified Water Specialist Practice Test

(CWS) Certified Water Specialist Practice Test

CWS Installation, Maintenance & Troubleshooting 3