Hot Water

Question 1

Centralised system

Answer 1

-where hot water is delivered from a central point to all hot water outlets
- water may be heated by boiler or immersion heater
-medium to large domestic such as 3 bed house

Question 2

Localised systems

Answer 2

-Single point / point of use
- water delivered by a small heater at the point where it was needed

Question 3

Centralised systems:
What is a open vented system

Answer 3

Hot water storage systems are fed from a cistern in the roof and contain a vent pipe that is open to atmosphere

Question 4

Centralised systems:
Unvented systems

Answer 4

-Hot water storage systems that are fed from the cold water main
- utilise an expansion vessel
- replaces FandE cistern

Question 5

Centralised systems:
Combination boilers

Answer 5

Instantaneous hot water on demand
No need for cylinder
Water heated by plated heat exchanger

Question 6

Open vented direct hot water storage system has one cylinder

Answer 6

Old gravity direct cylinder
- no coil in cylinder
- immersion heater
-cold feed 1” male thread, primary return 1” female, primary flow 1” female

Question 7

Open vented indirect system has two cylinders:
The double feed type has a coil
The single feed primatic has an air gap

Answer 7

Remember indirect double feed has a coil
- it has primary flow, primary return, cold feed