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

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

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.

What type of hot water cylinder is this

• Indirect double feed

• Indirect single feed

• Fortic

• Primatic single feed

What type of hot water stroage vessel is this

• Pressurised unvented

• Open vented

• Combination type

• Hot jacket type

What type of hot water storage cylinder is this

• Indirect single feed

• Primatic

• Combination "Fortic"

• Double feed unvented

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

• 
• 
• 
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What is this hot water component called

• Immersion heater

• Immersion spanner

• Expansion valve

• Immersion beater

The safety device incorporated inside an immersion heater is called

• A thermostat

• A thermal cut out

• A thermometer

• A resistor-stat

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