Installation guide

INSTALLATIONSECTION 3
32
WATER
CONNECTIONS
VENTED SYSTEMS
The water heater can be fed from a cold water feed cistern or static water tank.
A safety valve must be fitted as specified in BS 6644 Clause 9.
The safety valve must be fitted either directly to an upper tank tapping or not further than
one metre along the outlet flow pipe of size not less than the safety valve.
There must be no valve separating the heater from the safety valve.
The size of the discharge pipe must not be less than the nominal size of the safety valve
outlet. It should be self-draining and any water discharged must be visible and create no
hazard to persons in or about the building.
A low pressure open vented system can be used or where the natural circulating pressure
is insufficient, pumped circulation can be employed.
The heater must be fitted with an open vent pipe which is not valved and which rises
continuously to the open vent. It should be sized with reference to Technical Data, BS 6644
Clauses 9 and 10 and CP 342. Local Regulations and Bye-Laws must be observed when
installing the system.
Front Cold inlet / Front Hot outlet water connections
Assemble onto the 1
1
⁄2" hot water outlet (front) your required fitting using a suitable jointing
compound.
Assemble onto the
3
⁄4 BSP thread, the
3
⁄4 BSP coupler socket and drain cock using a
suitable jointing compound.
Water draw-off dead legs should comply with CP 342 Part 2, Table 1 and BS 6700.
NOTE:
When using a secondary return circuit, see Fig. 10 for the location of the return
tapping.
It is recommended that all water connections be made to the heater(s) using union fittings
for ease of servicing. Pipe support intervals should comply with CP 342, Part 2 Table 4.
After installation of the water system, open the main water supply valve, flush the system
and fill the heater. Open the hot taps to allow air to escape from the system. When the
system is free of air, close the taps and check for leaks at the thermostats, drain cock and
pipe connections on the heater.