Unit 216: Central heating principles

What are the 2 functions of an open vent pipe?

• To vent flue gases

• Maintain system at atmospheric pressure

• System overflow

• A safety device in case of system overheat

What is the minimum diameter of the vent pipe in an open vent system?

• 15mm

• 22mm

• 28mm

• 30mm

Which pipe allows the system water to expand and reach the F&E cistern?

• 15mm cold feed pipe

• 22mm vent pipe

• 28mm primary return

• 28mm primary flow

In a open vented system, what does the F&E cistern help to maintain?

• Water purity

• System pressure

• Static head

• Water temperature

What type of circulation does the two-pipe semi-gravity system use for the hot water circuit?

• Pumped circulation

• Gravity circulation

• Forced circulation

• Mixed circulation

What allows the heat emitters to achieve the same temperature in a two-pipe system?

• Mixing of flow and return waters

• Separate pipes for flow and return

• Use of a room thermostat

• Manual control of the pump

What does the room thermostat measure in a central heating system?

• Hot water temperature

• Room temperature

• Radiator flow rate

• Charge left in a drill battery

In a heating system, what is the role of the pump?

• To mix hot and cold water

• To circulate water through the heating circuits

• To control the temperature of hot water

• To reduce water pressure

What is the purpose of having a room thermostat in a heating system?

• To control the hot water temperature

• To switch off the heat source when the building is warm enough

• To mix flow and return waters

• To increase water pressure

Which component is responsible for heating the water in a central heating system?

• Programmer

• Boiler

• Room thermostat

• Feed and expansion cistern