Flow Regulating Valve (Not Supplied With Appliance); Hydraulic Connections On Mounting Frame; Hanging The Appliance - Bosch Worcester Greenstar HIU E Installation And Maintenance Instructions Manual

5.1.7

Flow regulating valve (not supplied with appliance)

NOTICE: The pressure differential across the primary
circuit of the heat interface unit must not exceed 80kPa
(800mbar) on units without a DPCV (differential
pressure control valve) as standard.
For units with internal DPCV (differential pressure
control valve) fitted, the maximum differential pressure
is 400kPa (4000mbar).
▶ A suitable means of control should be installed to
limit the differential pressure if the system design is
expected to exceed the limits above (depending on
the HIU model).
If the system design deems necessary, a Flow regulating valve (with
pressure test points at inlet and outlet) should be fitted and be located
in the district return pipe work at each Heat Interface Unit
• The function of the Flow regulating valve is to ensure that the correct
nominal flow rate is achieved at each Heat Interface Unit.
• By measuring the differential pressure across the regulating valve,
this can be converted into the corresponding district flow rate using
charts supplied by the manufacturer of the valve.
▶ If required the Flow regulating valve either; in the district return pipe
work [1] running up behind the appliance.
-or-
▶ In the district return pipe work [2] running down from the appliance.
1
Fig. 27 Flow regulating valve position
5.1.8

Hydraulic connections on mounting frame

▶ Fit the sealing washers to the service valves before hanging the
appliance.
– Bonded washers [1] for the District and Central Heating
connections.
– Blue PTFE washers [3] for the Domestic water connections.
Optional pressure gauge bracket [2].
▶ The pressure gauge can be moved from under the
expansion vessel and fitted in the optional bracket
position [2] on the mounting rail.
6 720 808 928 (2017/06)
Fig. 28 Service valves sealing washers
5.2

Hanging the appliance

Installing the main unit
▶ Lift and locate the hanging point [1] of the appliance onto the centre
hook [3] on the support bracket [2].
– Ensure the pipe connections fit into the isolation valve
connections.
▶ Ensure the unit is level and engaged on the support bracket, loosely
fit isolation valve connections [4].
▶ Tighten the isolation valve connections [4].
2
4
Fig. 29 Installation of main unit
3
1
2
Installation
1
1
2
3
25