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What must the cylinder of an unvented hot water system be fitted with to ensure the hot water never reaches 100°C?

• A) A pressure relief valve

• B) A range of safety (temperature) controls

• C) An automatic shut-off switch

• D) A thermostat

Where should the discharge pipes of an unvented hot water system be located?

• A) In a visible location

• B) In a safe place

• C) Near the water source

• D) Outside the building

Who must maintain the unvented hot water system?

• A) Any person

• B) A competent person

• C) The local authority

• D) The system manufacturer

How must installations of unvented hot water systems be notified?

• A) To the manufacturer

• B) To the local authority or self-certified (competent persons scheme)

• C) To the building owner

• D) To the public utilities company

What is the maximum temperature that the water within the storage cylinder of an unvented hot water system should not exceed?

• 90°C

• 100°C

• 110°C

• 120°C

What is the purpose of mechanical safety devices in an unvented hot water system?

• To heat the water to the desired temperature

• To ensure the water flows properly through the pipes

• To control the expansion of water and ensure the temperature does not exceed 100°C

• To cool down the water before it enters the storage cylinder

What does the pipework layout in the image show?

• Hot water outlet and cold water inlet via safety valves

• Cold water inlet via safety valves and unvented hot water outlet

• Hot water inlet and cold water outlet via safety valves

• Unvented cold water inlet and hot water outlet

What is the purpose of the expansion vessel in an indirect hot water system?

• To heat the water

• To store cold water

• To absorb excess pressure

• To filter impurities from the water

Where is the immersion heater located in the diagram of the indirect hot water system?

• Inside the system boiler

• Within the expansion vessel

• Inside the hot water cylinder

• Next to the filling loop

What is the function of the check valve in the hot water system layout shown?

• To regulate water temperature

• To prevent backflow of water

• To reduce water pressure

• To isolate the system for maintenance