Unit 308 Hot water (end of unit revision)

​Unit 308 Hot water systems

By Plumbers Cymoedd

And of unit revision

Use this link to open the hot water chapter then answer the questions on the following slides:

The_City_and_Guilds_Textbook_Plumbing_Book_1_for_t..._----_(6_Hot_water_systems).pdf

Multiple Choice

The purpose of the fitting is to

• Provide a method of releasing high pressure in the system

• Isolate the incoming cold water supply pipe from the mains

• Isolate the cold supply to the hot water storage cylinder

• Prevent the back flow of contaminated water into the mains

Multiple Choice

The purpose of a double check valve on a mains fed shower is to

• Prevent air locks

• Reduce outlet pressure

• Prevent backflow

• Reduce inlet pressure

Multiple Choice

The safest method of ensuring that a boiler connected to a hot water storage vessel cannot be re-activated during a period of de-commissioning, is to

• switch off the supply to the boiler at the fused spur socket outlet, tape the switch and carry on with the work

• contact the power supply company to advise that the power is being turned off and isolate the

  supply at the consumer unit by removing the fuse

• isolate the boiler from the electrical supply by turning off all the power at the mains, disconnect the boiler and tape the wires up

• isolate the boiler from the electrical supply at the consumer unit, remove and retain the fuse, and check for safe isolation.

Multiple Choice

What type of hot water cylinder is this

• Indirect double feed

• Indirect single feed

• Fortic

• Primatic single feed

Multiple Choice

What type of hot water stroage vessel is this

• Pressurised unvented

• Open vented

• Combination type

• Hot jacket type

Multiple Choice

What type of hot water storage cylinder is this

• Indirect single feed

• Primatic

• Combination "Fortic"

• Double feed unvented

Multiple Choice

What type of water heater is classed as a localised water heater

Multiple Choice

What is this hot water component called

• Immersion heater

• Immersion spanner

• Expansion valve

• Immersion beater

Multiple Choice

The safety device incorporated inside an immersion heater is called

• A thermostat

• A thermal cut out

• A thermometer

• A resistor-stat

Multiple Choice

What is this device called

• A TMV Thermostatic mixing valve

• A TSV Thermostatic shower valve

• A TRV Thermostatic radiator valve

• A TCV thermostatic cylinder valve

Multiple Choice

A pump is required on a secondary circulation system- what should the pump be made from

• Cast Iron

• Ferrous metal

• Any heating pump will do as long as its metal

• Bronze

Multiple Choice

What is the name for the metal strip placed inside a hotwater cylinder to help prevent corrosion

• Sacrificial lamb

• Corrosion anode

• Statistical Anode

• Sacrificial anode

Multiple Choice

At which temperature range does Legionnaire disease thrive

• 0-15

• 46-55

• 60-100

• 20-46

Multiple Choice

Which type of fitting must not be used on hot water pipework?

• Capillary fitting with a lead/tin solder.
• Proprietary push-fit plastic fitting.
• Non-manipulative compression fitting.
• Proprietary push-fit copper fitting.

Multiple Choice

What is the device shown

• Measuring water pressures.
• Measuring water flow rates
• Sizing hot water cylinders
• Determining the pH of water

Multiple Choice

The additional pipework circuit fitted to a hot water system to overcome dead-legs in the system is known as a

• primary circulation system
• Trace heating 
• secondary circulation system
• inverted loop system.

Multiple Choice

In which one of the following locations is it a requirement to insulate hot water system pipework?

• Surface mounted in a lounge.
• ‘Notched’ into timber first floor joists.
• In a loft space.
• Surface mounted in a bathroom

Multiple Choice

what component does this symbol represent?

• Single check valve 
• Double Check Valve 
• No Check Valve 
• Any Check valve 

Multiple Choice

What type of water heating device is shown

• Single point water heater
• Multipoint water heater
• Combination cylinder.
• Direct cylinder

Multiple Choice

What type of shower system is shown

• Instantaneous electric shower.
• Pumped shower with double impellor pump.
• Pumped shower with single impellor pump
• Gravity feed shower

Multiple Choice

What type of hot water system is shown

• Direct system heated by immersion heater.
• Indirect system with single feed cylinder
• Unvented system fed by a boiler.
• Direct system heated by a combination boiler.

Multiple Choice

Water ________ when it is heated.

• contracts
• cools
• expands
• heat

Multiple Choice

What type of shower is this?

• Instantaneous electric shower
• Thermostatic bar mixer type
• Gravity fed shower
• Bath mixer shower

Multiple Choice

Where would state the maximum flow rate and temperature for a particular pumped shower that has been installed?

• BS6700
• The Water Regulations
• The manufacturer’s instructions
• Building Regulations part G.

Multiple Choice

If a flow switch on a pumped shower does not work, what would be the result?

• The water temperature will remain too high
• The pump will not be activated by the electrics
• The pump will have restrictive water flow
• The water temperature will remain too low

Multiple Choice

Under the Water Regulations, what can category 2 water be described as?

• Wholesome water
• Water representing a slight risk to health
• Wholesome water with its aesthetic qualities impaired
• Water representing a severe risk to health.

Multiple Choice

What type of hot water storage cylinder is shown

• Single feed indirect cylinder
• Double  feed indirect cylinder
• Direct cylinder
• Unvented cylinder

Multiple Choice

What type of hot water system is shown in figure

• Indirect system with single feed cylinder
• Combination cylinder system.
• Direct system
• Indirect system with double feed cylinder

Multiple Choice

What type of shower mixer can limit the water temperature from a shower head (rose) in response to changes in the quantity of hot or cold water supplied to the mixer valve?

• Manual mixer valve
• Mid position mixer valve.
• Twinflow mixer valve.
• Thermostatic mixer valve

Multiple Choice

What is the purpose of undertaking a visual inspection before soundness testing a hot water system? To

• chlorinate the system to protect against legionella
• check the water flow rate in the system
• check the water pressure in the system
• confirm that the system is ready for soundness testing

Multiple Choice

What is the minimum size of hot water pipework from a small combination boiler in a domestic property?

• 15mm
• 50mm
• 150mm
• 25mm

Multiple Choice

Which one of the following can be fitted to a hot water storage cylinder to provide protection against type 1 pitting corrosion?

• Sacrificial anode.
• Pressure reducing valve.
• Pressure relief valve
• Jam sandwich 

Multiple Choice

A low pressure manual shower mixer valve must be supplied with

• cold water from the supply pipe and hot water from storage
• hot and cold water from storage
• hot and cold water from the supply pipe
• hot water from the supply pipe and cold water from storage

Multiple Choice

What is the name of the tool shown

• Immersion heater spanner.
• Water pump pliers
• Circlip pliers.
• Water pump pliers

Multiple Choice

What type of backflow protection device should be fitted to a mixer tap fed with cold water from a supply pipe that permits mixing of hot and cold water in the valve body?

• Pipe interrupter
• Anti-vacuum valve
• Double Check valve
• Single check valve

Multiple Choice

Which of these is NOT an instantaneous water heater

Multiple Choice

What should be the length of the horizontal pipe from the open vent on leaving the cylinder

• 400mm

• 350mm

• 450mm

• Doesn't matter any size you like

Multiple Choice

What is the name of pipe number 3 on this indirect double feed cylinder

• Primary return

• Primary feed

• Primary school

• Secondary circulation

Multiple Choice

What is a dead leg

• Something Footballers get when tackled

• A length of pipe leaving the hot water cylinder carrying hot-water to an appliance

• An air lock in the hot water cylinder

• The pipe that enters the hot water cylinder

Multiple Choice

What device is fitted to a cylinder and used to control the temperature of stored hot water to avoid over heating and saving energy

Multiple Choice

This component connects from the top of the cylinder to the shower. What is it called?

• Norfolk flange
• Feltham Flange
• Essex Flange
• Suffolk Flange

Multiple Choice

What is this component called?

• Mid Position Valve
• Drain Off Valve
• Thermostatic Mixing Valve
• Radiator Valve

Multiple Choice

What is the hydraulic test pressure when carrying out soundness test?

• 3 x working pressure
• 2 x working pressure
• 1.5 working pressure
• 1 x working pressure

Multiple Choice

Blockages in pipework can be caused by?

• Flux
• Limescale build up
• Water being too cold
• Water being to slow

Multiple Choice

Pipe work systems can be disinfected using which chemical?

• Copper Cleaner
• Sodium
• Salt
• Chlorine

Multiple Choice

How is soundness testing carried out on copper pipe

• Air test
• Hydraulic Test
• Flow test
• Power flush

Multiple Choice

What separates the primary and secondary water from mixing?

• water
• gap
• air bubble
• bubble bath

Multiple Choice

Poor flow rate can be caused by?

• Valeves that are partially open
• Valves that are fully open
• Drain off Valves
• Pipe work not being clipped

Multiple Choice

What size are the Primary flow and return pipes?

• 10 mm
• 15mm
• 22mm
• 32mm

Multiple Choice

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

• Booster pump for a shower
• Indirect hot water cylinder
• Shower mixer valve
• External bib tap

Multiple Choice

A rigid pipework hot water system has a working pressure of 4bar. At what pressure should the pipework be tested for soundness?

• 1bar for 60 minutes
• 1½ times the working pressure for 15 minutes
• 4bar for 30mins then 6bar for 15 minutes
• 6 bar for one hour

Multiple Choice

In a customer’s property, the CWSC supplies both the hot and cold water systems. The minimum size of this cistern is:

• Equal to 48 hours’ worth of water
• 230 litres
• 100 litres
• Twice the size of the domestic hot water cylinder 

Multiple Choice

What is used at a basin outlet to prevent contamination of the water system?

• AUK2 air gap
• AUK3 Air gap
• AG air gap
• AG4 air gap

Multiple Choice

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

Multiple Choice

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

Multiple Choice

A temperature sensing cartridge can be found in

• a shower mixer valve

• An electric immersion heater for a hot water storage cylinder

• A screened warning pipe assembly for a storage and feed cistern

• A pressure reducing valve

Multiple Choice

Which one of the following provides the legal requirements for the installation of hot water distribution pipework?

• Water Regulations.

• Construction Regulations.

• Building Regulations

• British Standard 6700

Multiple Choice

If hard water is allowed to be heated above 65⁰C, what could be the consequence in the system

• Legionella could grow

• The blending valve would fail to work

• The efficiency could be affected by limescale

• The pressure relief valve would open

Multiple Choice

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

• No longer than 2.5m, as stated in BS EN 806

• Always heated to above 500C

• As short as possible

• Disinfected annually under a PPM program

Multiple Choice

Which one of these hot water storage cylinders is a direct one