CONTRACTOR EXAMINATION
250 Practice Questions • Correct Answers • Rationales • 2026 Edition
IMPORTANT: This is an original exam-style practice bank, not a reproduction of leaked, secure, or unreleased PSI/AZ ROC examination questions. The
current official Arizona ROC/PSI C-6 outline lists 30 questions, a 70% minimum passing score, and 75 minutes, with content areas in filtration/circulation,
maintenance/operation, accessories/associated trades, plaster, pool repairs, and OSHA safety. The 250 questions below expand those domains for intensive
study. Scope/licensing items are based on current Arizona ROC information.
Filtration & Circulation Systems
1. What is the primary purpose of a pool circulation system?
To heat the water
To move water through treatment and return it to the pool
To raise total alkalinity
To remove calcium hardness
Rationale: Circulation moves pool water through the pump, filter, and treatment equipment so contaminants can be removed and
disinfectant can be distributed.
2. A pump strainer basket is primarily intended to:
Trap large debris before it reaches the impeller
Increase chlorine concentration
Measure pH
Reduce water temperature
Rationale: The pump strainer catches leaves and other larger debris that could damage or obstruct the impeller.
3. A filter pressure gauge reading that is substantially higher than the clean starting pressure most commonly
indicates:
Restricted flow through the filter
An empty skimmer basket
Excessive pool volume
Low water temperature
Rationale: As a filter loads with debris, resistance to flow increases and the filter pressure typically rises.
4. A very low filter pressure accompanied by weak return flow can indicate:
A blockage or air leak on the suction side
A perfectly clean filter
Excessive filter media
High total alkalinity
Rationale: Low pressure with poor flow points toward a suction restriction, air leak, or another condition preventing normal pump
flow.
Arizona CR-6 Swimming Pool Service & Repair — 250-Question Practice Bank Page 1
, Real pool-service technician inspecting pump equipment. Source: FTG Pool Service & Repair.
5. Why should the pump never be operated without adequate water flow through the pump?
The motor will automatically increase chlorine
The pump can lose prime and equipment can be damaged
The filter will backwash itself
The pool will become more alkaline
Rationale: Running without sufficient water can cause loss of prime and overheating or seal damage.
6. The pump impeller is responsible for:
Creating the pressure/flow that moves water
Testing sanitizer concentration
Removing dissolved calcium
Supporting the pool deck
Rationale: The rotating impeller imparts energy to the water and produces the flow needed for circulation.
7. A skimmer's main hydraulic function is to:
Collect surface water and floating debris
Heat the water
Measure electrical current
Lower calcium hardness
Rationale: Skimmers draw water from the surface where oils and floating debris accumulate.
8. A clogged skimmer basket is likely to cause:
Reduced suction and circulation
Higher-than-normal flow
Automatic pH correction
Increased filter area
Rationale: A blocked basket restricts the suction path and can reduce pump flow.
9. What is the safest practice before opening a pump strainer lid?
Increase pump speed
Stop the pump and relieve trapped pressure
Add acid
Close every return fitting permanently
Rationale: The pump should be off and pressure relieved before opening the strainer housing.
Arizona CR-6 Swimming Pool Service & Repair — 250-Question Practice Bank Page 2
, 10. A multiport valve is commonly used with which type of filter?
Sand filter
Cartridge filter only
UV lamp only
Heat exchanger only
Rationale: Sand filters commonly use multiport valves to select filter, backwash, rinse, waste, recirculate, and other modes.
11. The purpose of the RINSE position after backwashing a sand filter is to:
Settle and flush the filter bed before returning to FILTER
Add calcium to the pool
Drain the pool completely
Increase pump voltage
Rationale: Rinse sends water through the bed in the normal direction while discharging residual dirt before filtration resumes.
12. Backwashing a sand filter means:
Reversing water flow through the filter media to remove trapped debris
Adding sand to the pool
Heating the filter tank
Draining the pump oil
Rationale: Backwashing reverses flow through the media and carries accumulated dirt to waste.
13. A cartridge filter is cleaned primarily by:
Removing the cartridge and washing the pleats according to manufacturer instructions
Backwashing it through a multiport valve
Adding acid to the cartridge
Running the pump dry
Rationale: Cartridge elements are removed and cleaned, commonly with a hose, following the manufacturer's instructions.
14. The purpose of filter media is to:
Capture suspended particles from circulating water
Generate electrical power
Raise water temperature
Prevent all evaporation
Rationale: Filter media provides a physical barrier that removes suspended contaminants.
15. A sudden drop in flow after a pump has been operating normally may be caused by:
A clogged impeller
A freshly cleaned filter
A larger suction line
A clean skimmer basket
Rationale: Debris at the impeller can reduce the pump's ability to move water.
16. Air bubbles continuously returning through pool return fittings may indicate:
Air entering the suction side
Excessive calcium hardness only
A perfectly sealed system
A full chemical feeder
Rationale: Persistent air in the return stream can result from a suction-side air leak or low water level.
17. A pump that repeatedly loses prime should first be evaluated for:
Suction-side air leaks, water level, and valve positions
Pool color
Deck texture
Calcium scale only
Rationale: Prime loss is commonly related to insufficient water at the skimmer, suction leaks, or incorrect valve positions.
Arizona CR-6 Swimming Pool Service & Repair — 250-Question Practice Bank Page 3
, 18. Why is a clean starting filter pressure important?
It provides a baseline for deciding when cleaning is needed
It determines the pool's pH
It replaces a flow meter
It measures chlorine demand
Rationale: Recording clean pressure gives the technician a reference point for detecting filter loading.
19. If a filter normally operates at 12 psi after cleaning and now reads 20 psi with reduced flow, the likely action
is:
Inspect and clean/backwash the filter as appropriate
Increase the filter pressure further
Close all returns
Add salt only
Rationale: A significant pressure rise with reduced flow indicates filter restriction and calls for appropriate cleaning.
20. The most direct way to confirm whether a pump is receiving adequate suction water is to:
Inspect water level, suction valves, basket, and visible flow conditions
Measure pool pH only
Check the deck temperature
Add algaecide
Rationale: Hydraulic troubleshooting starts with verifying water level, valve positions, basket condition, and suction flow.
21. A check valve is used to:
Help prevent reverse flow when the pump stops
Raise chlorine residual
Lower pH
Filter sand
Rationale: Check valves permit flow in one direction and can help prevent unwanted reverse flow or draining.
22. A plumbing union is valuable because it:
Allows equipment to be disconnected more easily for service
Raises filter pressure
Replaces a safety barrier
Measures water chemistry
Rationale: Unions provide serviceable connections around pumps, filters, heaters, and other equipment.
23. A valve that is only partially open can:
Restrict flow and increase hydraulic resistance
Guarantee maximum flow
Increase filter area
Neutralize chlorine
Rationale: Partially closed valves create additional resistance and may reduce system flow.
24. The best general reason to keep suction and return piping free of unnecessary restrictions is to:
Reduce hydraulic losses and support efficient circulation
Increase chemical consumption
Prevent all evaporation
Increase pool depth
Rationale: Unnecessary restrictions increase head loss and can reduce pump performance.
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