pp2 Central Heating System 1.3

What is the term used for older central heating systems that rely on the principle of convection for heat circulation?

• Forced circulation

• Two-pipe semi-gravity system

• Gravity circulation

• Pumped systems

What is the primary function of the open vent pipe in a one-pipe semi-gravity system?

• To discharge steam/water in a fault condition

• To allow filling of the system from the F&E cistern

• To control room temperature

• allow for expansion and contraction to provide a safety outlet in case of overheating

What is the drawback of a one-pipe semi-gravity system in terms of the temperature of each radiator?

• The temperature of the radiators is unpredictable

• Each radiator is progressively hotter than the previous

• Each radiator is progressively cooler than the previous

• All radiators have the same temperature

What is the purpose of the feed and expansion (F&E) cistern in a one-pipe semi-gravity system?

• To accommodate system expansion

• To provide static head for the heating system

• All of the above

• To keep the system topped up after slight water loss

In a two-pipe semi-gravity system, what controls the heating by switching off the pump?

• Programmer

• Room thermostat

• 22mm vent pipe

• Boiler

What is the advantage of a two-pipe semi-gravity system in terms of heat emitters?

• Heat emitters are not efficient

• All heat emitters reach the same temperature

• All heat emitters have different temperatures

• Heat emitters are not affected by the system

What is the disadvantage of a two-pipe semi-gravity system in terms of heat control?

• Uncontrolled heat

• Controlled heat

• Heat is not distributed evenly

• Heat emitters do not reach the same temperature

What is the primary difference between a one-pipe semi-gravity system and a two-pipe semi-gravity system?

• The number of pipes used

• The type of heat emitters used

• The control mechanism used

• The type of boiler used

What is the purpose of the neutral point in a one-pipe semi-gravity system?

• To ensure equal suction by the circulating pump

• To keep the system topped up after slight water loss

• To provide static head for the heating system

• To allow filling of the system from the F&E cistern

What is the recommended minimum height for the open vent pipe in a one-pipe semi-gravity system?

• 350mm

• 450mm

• 250mm

• 150mm