Rayburn Heatranger 440, Installation Instructions Manual

Page: 12 / 44

Flow and return pipework between cooker diverter valves
must be 28mm diameter minimum.
Space and water heating systems should be in
accordance with the relevant recommendations of BS
5410: Part 1.
In a combined central heating and domestic hot water
system, the hot water storage vessel must be of the
indirect cylinder type to BS 1566: Part 1. The hot water
storage vessel should be insulated with not less than
75mm thick mineral fibre or its equivalent.
Cisterns and pipework should not be situated in areas
which may be exposed by freezing conditions and should
be insulated.
Draining taps must be located in accessible positions
which permit the draining of the whole system, including
the heat storage vessel. Draining taps should be at least
1/2 in BSP nominal size and be in accordance with BS
2879.
The appliance boiler section should be connected to a
cistern water supply, subject to a maximum head of
18.25m. The heating system must be designed (and
adjusted if necessary) to give temperature differential
across the boiler at full output of 10-14°C. When
horizontal runs are used the pipes should rise upwards in
the direction away from the appliance.
Circulating Pump
It is recommended that the selected pump be sized to suit
the boiler pressure loss and therefore adequate to give
the required temperature differential between the flow and
return.
The pump should be able to meet the requirements of the
system design and fitted in a readily accessible position.
Isolating Valves
Isolating valves (preferably of the keyless type) must be
fitted to the inlet and outlet of the circulating pump to
facilitate service and replacement of parts without
draining the system.
Inhibitor
A corrosion inhibitor MUST be added to the heating
system to protect the heat exchanger and pipework.
Inhibitor must also be replaced if the system is drained
after installation. As a precaution the heating system
MUST also be flushed out prior to the addition of the
inhibitor to ensure any flux, debris removed.
Site requirements
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WATER CIRCULATION SYSTEM