CWS Installation, Maintenance & Troubleshooting 2 — Questions and Answers
Question 1: When installing a water softener, the bypass valve should be in which position during the initial startup and brine tank filling?
- Open (service) position
- Bypass position (Correct answer)
- Partially open position
- Closed position
Correct answer: Bypass position
The bypass valve should be in bypass position during initial setup to prevent untreated water from entering the system before it is properly charged and tested.
Question 2: A customer reports their water softener regenerates every day but water still feels hard. What is the most likely cause?
- The salt level is too high
- The resin bed is exhausted or fouled (Correct answer)
- The regeneration cycle is too frequent
- The bypass valve is open
Correct answer: The resin bed is exhausted or fouled
Resin fouled by iron, chlorine, or other contaminants loses exchange capacity, causing hardness breakthrough even with frequent regeneration.
Question 3: What is the purpose of the air check valve in a brine tank?
- To prevent salt bridges from forming
- To regulate water pressure entering the tank
- To stop brine draw when the brine tank reaches a low water level (Correct answer)
- To control the flow rate of brine into the resin tank
Correct answer: To stop brine draw when the brine tank reaches a low water level
The air check (or safety float) stops brine from being drawn into the resin tank once the brine tank water level drops to the preset minimum, preventing air from being pulled into the system.
Question 4: During installation of an RO system, permeate tubing from the membrane housing should be connected to which port?
- The reject/concentrate port
- The feed water inlet port
- The product water outlet port (Correct answer)
- The drain port
Correct answer: The product water outlet port
The product (permeate) water outlet port directs purified water to the storage tank, while the reject port sends concentrate to the drain.
Question 5: A UV disinfection system log shows that the UV intensity alarm activated. What is the first corrective action a technician should take?
- Replace the UV lamp immediately
- Clean the quartz sleeve (Correct answer)
- Increase water flow rate
- Check and replace the UV sensor
Correct answer: Clean the quartz sleeve
A fouled quartz sleeve is the most common cause of low UV intensity; cleaning it is the first and least costly corrective step before replacing components.
Question 6: What minimum clearance above a water softener is typically recommended to allow for resin replacement?
- 6 inches
- 12 inches
- 24 inches (Correct answer)
- 36 inches
Correct answer: 24 inches
A minimum of 24 inches of overhead clearance is generally required to remove the control valve and access the resin tank for media replacement.
Question 7: Which symptom most strongly indicates that a sediment pre-filter is due for replacement in a residential treatment system?
- Increased water temperature at the tap
- Noticeable drop in water pressure throughout the house (Correct answer)
- Higher than normal TDS reading
- Salt usage has increased in the softener
Correct answer: Noticeable drop in water pressure throughout the house
A clogged sediment filter restricts flow, causing a measurable pressure drop across the filter and reduced pressure at downstream fixtures.
CWS Installation, Maintenance & Troubleshooting 2
When installing a water softener, the bypass valve should be in which position during the initial startup and brine tank filling?