Q.
What does it mean by Direct and Indirect water supply. How about Hot and Cold?
A.
Direct or indirect refers to how the water is distributed in the piping system of the house. Hot or Cold refers to hot water systems and cold water (as supplied from the water source) by the main piping outside.
This question always come out in past years, as shown in link below.
2011 Q5a
2012 Q4b
2013 Q2b
2014 Q5a
2015 Q1b
Indirect Water Supply
The below diagram shows an indirect hot water cylinder, known as indirect because the hot water from the boiler (primary circulation) doesn't come into direct contact with the hot water in the cylinder (secondary circulation) - this water being used for washing and cooking.
Ref:
http://www.arca53.dsl.pipex.com/index_files/hwstore.htm
Direct water supply
A direct water supply system is one where the raising main feeds directly the cold water taps and a multi point water heater.
The mains water comes in via a rising main and directly feeds all the cold taps and a multi point water heater - so all the taps and other water feeds are at mains water pressure. Note that in this article, we are dealing with just the hot and cold water supplies to the taps etc, we are not dealing with the central heating system.
Ref:
Direct water supply, available at
http://www.practicaldiy.com/plumbing/water-supply/direct-water-supply.php