Hot Water Recap Mock Exam

The water supply (water fittings) regulations 1999 lay down:

• The regulations covering all internal and external hot and cold water systems for dwellings

• The guidance for good practice when installing hot and cold pipework in a dwelling

• The regulations that cover hot water systems only

• The guidance for internal hot and cold water systems only within a dwelling.

Which one of the following hot water components should be fixed using flexible connections?

• Indirect hot water cylinder

• Shower mixer valve

• Booster pump for a shower

• External bib tap.

To prevent electrolytic corrosion taking place in a system, where can the magnesium rod be placed?

• The cold water storage cistern

• The hot water cylinder

• The circulator

• The open vent.

Which of the following appliances is most likely to offer the customer low pressure at a hot water outlet?

• Combination boiler

• Direct cylinder

• Combination unit

• Indirect cylinder

What is this item?

• Pressure/temperature relief valve

• Double check valve

• Stop valve

• Blending valve

If hard water is allowed to be heated above 65°C, what could be the consequence in the system?

• Legionella could grow

• The blending valve would fail to work

• The pressure relief valve would open

• The efficiency could be affected by limescale.

To overcome a dead leg for a hot water draw-off point, what course of action could be taken?

• Install secondary circulation

• Install a more powerful circulator

• Increase the size of the hot water cylinder

• Increase the temperature on the cylinder thermostat.

A customer has intermittent flow of hot water from their bath tap – what is the most likely cause of the problem?

• Too little head pressure

• Too much head pressure

• Air lock

• Faulty float operated valve.

What is the primary function of the open vent on a domestic hot water system?

• Safety relief pipe

• Take up a hydraulic shunt

• Allow hot water to be distributed at a controlled pressure

• To balance the feed from the CWSC

To prevent the risk of legionella forming in a dead leg it should be:

• No longer than 2.5 metres, as stated in BS6700

• Disinfected annually under a PPM program

• As short as possible

• Always heated to above 50°C