Contractor Exam Questions And

CA D81 Pool Solar Heating Systems Contractor Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• Which type of solar collector is most commonly used for residential

pool heating?

• Flat-plate collector
• Evacuated tube collector
• Parabolic trough collector
• Concentrated solar power collector
• Flat-plate collector

Flat-plate collectors are cost-effective, durable, and ideal for low- temperature applications like pool heating.

• What is the primary function of a check valve in a pool solar heating

system?

• Increase water pressure
• Prevent backflow
• Filter debris
• Control solar exposure
• Prevent backflow

Check valves ensure that heated water does not flow back into the pool during periods of low or no circulation.

• Which material is most commonly used for solar pool heating piping?
• Copper

B. CPVC

• Polypropylene 1 / 3

D. PVC

D. PVC

PVC is cost-effective, resistant to pool chemicals, and easy to install.

• What is the recommended slope for solar collector piping to ensure

proper drainage?

• 1/8 inch per foot
• 1/4 inch per foot
• 1/2 inch per foot
• Level
• 1/4 inch per foot

A 1/4 inch per foot slope prevents airlocks and allows proper drainage of the system.

• What is the ideal pool water temperature range for most solar heating

systems?

A. 60–70°F

B. 70–85°F

C. 85–95°F

D. 95–105°F

B. 70–85°F

Solar pool heating systems are designed to maintain comfortable swimming temperatures within this range.

• What component measures the water temperature at the solar collector?
• Flow switch
• Thermostat
• Temperature sensor
• Pressure gauge
• Temperature sensor

Temperature sensors monitor collector temperature to optimize system performance and protect equipment.

• Which method is used to control water flow through solar collectors?
• Manual valves only
• Automatic solar controller
• Pool pump timer
• Pressure relief valve
• Automatic solar controller

Controllers regulate flow based on collector temperature and pool temperature, maximizing efficiency. 2 / 3

• What is the typical lifespan of a PVC solar collector panel?
• 1–5 years
• 5–10 years
• 10–15 years
• 15–20 years
• 10–15 years

High-quality PVC panels are durable and resistant to UV degradation for over a decade with proper maintenance.

• When should a pool solar heating system be winterized in colder

climates?

• Early fall
• Late spring
• Mid-summer
• After the first frost
• Early fall

Winterizing prevents damage from freezing temperatures by draining or bypassing water from the collector.

• Which type of pump is most suitable for circulating water

through a solar pool heating system?

• Centrifugal pump
• Gear pump
• Diaphragm pump
• Peristaltic pump
• Centrifugal pump

Centrifugal pumps provide consistent flow, are efficient, and are commonly used in pool systems.

• What is the main benefit of using black PVC in pool solar

collectors?

• Lower cost
• Improved heat absorption
• Chemical resistance
• UV protection
• Improved heat absorption

Black surfaces absorb more solar radiation, increasing water heating efficiency.

• Which safety device prevents overheating in a pool solar heating

system?

• / 3