14
Unvented system
(See figure 5)
To install an STATE WATER HEATERS
on an unvented cold water supply
system a kit of valves and fittings fisted
by the water reseach centre and
complying with part G3 of the current
building regulations should be used.
Installation should be carried out
generally as shown on the following
diagram.
1) Manual gas valve
2) Stop valve
3) Expansion vessel
4) T&P safety valve
5) Non return valve
6) Circulation pump
7) Drain valve
8) Pressure limiting valve
9) Expansion valve
Figure 5 - Connection diagram unvented
systems
A ) Gas supply
B) Hot water dilevery
C) Cold water inlet
D) Hot water taps
E) Return circulation
