8202L3CHPPT2

Modern domestic central heating systems are categorized based on what two factors?

• The type of fuel used and the cost

• The way the system is filled with water and the pressure it operates at

• The size of the house and the number of radiators

• The brand of the system and the installation date

What is a characteristic of low pressure, open-vented systems?

• They are not connected to the mains water supply

• They require a constant supply of electricity to operate

• They are fed from a feed and expansion cistern located at high level

• They are the most modern type of system available

Sealed, pressurised systems are different from low pressure, open-vented systems because they:

• Use gravity to operate

• Are fed directly from the mains cold water

• Do not use a feed and expansion cistern

• Both B and C are correct

What is a modern example of a sealed, pressurised system?

• A gravity system

• A fully pumped system

• A combination boiler system

• An open-vented system

What does a combination (Combi) boiler system only require for its operation?

• A time switch and a room thermostat

• A pilot light and a chimney

• A fuel tank and a water pump

• A heat exchanger and a blower

What do modern combination boilers contain for safety control?

• A thermostat and a timer

• An expansion vessel or a pressure relief valve

• A fuel gauge and a carbon monoxide detector

• A pilot light and a smoke detector

What additional feature do most 'combis' have?

• A backup heating element

• An integral filling loop

• A solar panel connection

• A programmable timer

What is the function of the expansion vessel in a combination boiler system?

• To regulate the room temperature

• To provide the main cold water supply

• To accommodate water expansion as it heats

• To discharge excess water from the system

What is the purpose of the filling loop in the combination boiler system?

• To provide a pathway for heating flow

• To allow for manual addition of water to the system

• To control the temperature of the hot water supply

• To connect the room thermostat to the boiler

What is the purpose of an automatic bypass valve in a boiler system?

• To increase water pressure across the boiler

• To control water flow and maintain a minimum flow rate through the boiler

• To completely stop the water flow through the boiler

• To allow for maximum circulation pressure when alternative water paths are open