Vented Systems, Hiflo Range - andrews 24/39 Installation And Service Manual

Issue 2 14/07/16
3.9.7

Vented systems, HIflo Range

The water heater must be fed from a cold water feed cistern or
static water tank.
Note
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 1 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 be not 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.
Water draw-off dead legs should comply with CP 342 Part 2,
Table 1 and BS 6700.
Fig. 13
Models 65/173, 81/264. Optional top inlet/outlet water
connections
Select the cold/hot location required (i.e. top inlet/outlet or front
inlet/outlet) and, using a suitable jointing compound, blank off
the two ports not required.
All Models. Front inlet/outlet water connections
Models 32/143. Optional rear inlet/outlet water connections
Assemble onto the 3/4 BSP thread, the 3/4 BSP coupler socket
(1) and drain cock using a suitable jointing compound. Select
the Cold/Hot location required and using a suitable jointing
compound, blank off the two ports not required.
Models 32/143, 62/341, 54/418, 54/440
A 3/4 BSP thread connection is available at the top of the
heater, this is suitable for a Automatic Air Vent if required (Not
supplied).
Note
When using a secondary return circuit, see Fig 13 for the
locations of the return tappings.
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.
Installation 3
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