Vented and unvented systems

When a hot tap is opened, a certain amount of cold water is drawn off and allowed to run to a drain before the hot water arrives. This wasted cold water is known as a

What is the max length of pipe run for pipes sized between 12 and 22mm?

• 20m

• 12m

• 8m

• 3m

Which of the following does not describe a hot water system?

• Centralised

• localised

• unvented

• heat only

What type of system is this?

• Direct

• Instantaneous

• Indirect

• Single point

In both direct and indirect systems, the hot water cylinder is what type of component?

• Localised

• Centralised

• Instantaneous

What type of system is this?

• Heat only

• Combination boiler

• single point water heater

• Thermal store

This is a _______ store cylinder

A shower is a type of _________ hot water system

Instantaneous: This means that the hot water is heated up on demand. An outlet is opened so water flows and this activates the heat source. As the water flows through the unit, so the cold water is heated to temperature through quick heat transfer. The flow rate of water through the unit will determine the outlet temperature.

• True

• False

The hot water draw off from the cylinder should be at least how long before connecting to the open vent pipe?

• 400mm

• 450mm

• 500mm

• 600mm