Which of the following is a requirement for all immersion heaters installed today?

• They must have a built-in timer.

• They require a reset button or cut-out device.

• They must be installed outdoors.

• They require a manual switch.

What is the power rating of domestic immersion heaters?

• 1kW

• 2kW

• 3kW

• 4kW

Which of the following lengths is NOT mentioned as a common size for immersion heaters?

• 27

• 14

• 11

• 20

What component is easily replaced in an immersion heater?

• The heating element

• The thermostat

• The outer casing

• The power cord

What are open vented combination units?

• Units where the cylinder and cold water storage cistern are separate.

• Units where the cylinder and cold water storage cistern are joined together.

• Units that require extensive plumbing to connect to the mains feed.

• Units that are difficult and time-consuming to install.

What is a disadvantage of open vented combination units?

• They are difficult to install.

• They require a lot of maintenance.

• They lack head pressure.

• They are expensive.

Where are open vented combination units commonly found?

• In large houses.

• In commercial buildings.

• In flats.

• In industrial plants.

What is an advantage of open vented combination units?

• They provide high head pressure.

• They are easy and quick to install.

• They are very expensive.

• They require extensive plumbing.

What is the term used to describe the temperature difference between the top (hot) and bottom (cooler) of a hot water cylinder?

• Temperature gradient

• Temperature stratification

• Temperature inversion

• Temperature layering

What is the purpose of a baffle installed in some hot water cylinders?

• To increase the water temperature

• To prevent incoming cold water from mixing with hot water

• To decrease the water temperature

• To allow cold water to mix with hot water