water regulation

British standards 8558

direct system

-contains back boiler -contains hot water immersion heater

in-direct system

-single feed ,self venting -double feed with hot water heating cooler

instantaneous hot water heaters

-single point heaters -multipoint heaters

combination boiler

-combi boiler

suitable materials

-copper -bronze -stainless steel

open vented direct

no coil

open vented indirect

has a coil

single feed system

separates secondary water from primary (heating) water

thermal stores

a multipoint water system where cold water passes through a heat exchanger

gas fired instantaneous multipoint water heaters

uses the principle of pressure. when one tap is on and creates a different pressure on the other tap.

combination(combi) boiler

heats up by a water to water heat exchanger

single point heaters

only used where lack of hot water or point where hot water is difficult to reach

instantaneous single point water heater

this provides instant hot water to a single appliance usually for: hand wash or electric showers

storage single point water heaters

small use of heaters that store small amount of water, usually less than 15 litres

taps, valves, FoVs , showers and backflow protection

unit H/602/2697

directed heated storage system

heated by a small water boiler, or an electric immersion heater

indirectly heated storage cylinders(single feed)

self ventilating incorporates a storage cylinder with a special heat exchanger

indirectly heated storage cylinders(double feed)

contains a coil type heat exchanger

combination cylinder

contains hot storage cylinder with cold water feed cistern

mains fed multipoint heaters

gas fired or run by electricity. drawn by cold water mains

main fed combi boiler

hot water and central heating system in single appliance. heating water to water heat exchanger.

mains fed point of use water heaters

hand wash- small heater, usually 3kw electric shower- outputs 12kw, low pressure cut out against scalding