A.O. Smith BFM 80 - Manual (Page 12)

12
IM D -0 06 6-R 0
Depending on the length and insulation of the water
piping and the water demand frequency, it may be
necessary to install a circulation system on the drain
cock. The return pipe of the circulation piping can be
fitted on the top of the drain cock after the sealing plug
has been removed (see figure 6).
Unvented
To install an A.O. Smith water heater on an unvented
cold water supply system a kit of valves and fittings
listed by the water research centre and complying with
part G3 of the current building regulations and BS 7206
should be used. Installation should be carried out
generally as shown on diagram 7. Kits are available
from A.O. Smith or our distributors.
Figure 6
1) Gas cock
2) Stop valve
3) Expansion vessel
4) T&P valve
5) Non-return valve
6) Circulation pump
7) Drain valve
8) Pressure limiting valve
9) Expansion valve
A) Gas supply
B) Hot water
C) Cold water
D) Hot water supply
E) Return circulation
Diagram 7 - Connection diagram (unvented system)