Use In Hard Water Areas; Connecting To The Heating System Without A Bypass - Worcester GREENSTORE Instruction Manual

Use in hard water areas

Normally there is no need for water treatment to prevent scale formation.
In areas where temporary water hardness exceeds 200ppm, consideration may need to be given to the fi tting of a scale
prevention device. In such circumstances the advice of the local water authority should be sought.

Connecting to the heating system without a bypass:

The heat pump can be connected to the heating system without a bypass, as the circulation in the heat pump and the
heating system is managed by the integrated pump G2 (P2). However minimum fl ow of at least 70% of the nominal fl ow
(see the table below) must be maintained throughout the year. Thermostatic radiator valves should be fully open and
underfl oor heating systems should have at least half of the coils fully open at all times. The control unit gives an alarm
when the return differential temperature exceeds 13ºC.
If the heating system is designed so that at least 70% of the nominal fl ow cannot be guaranteed, the heat
pump should be connected using a bypass and an external main pump G1 (P1).
Hot water function:
Hot water production is started by the hot water sensor T3 (GT3), and is stopped by the return sensor T9 (GT9).
Heating system pump
The circulation pump G2 (P2) is a Wilo Star 25/6-130.
Maximum system pressure drop in the
heating system
The maximum system pressure drop and the minimum fl ow that
the integrated circulation pump can operate with is presented
in the table. If the minimum fl ow cannot be guaranteed a
bypass and an external main pump G1 (P1) should be
installed. Ensure that TRV's cannot close down and restrict the
required fl ow.
Heat pump model Nominal fl ow [*]
Greenstore 6
Greenstore 7
Greenstore 9
Greenstore 11
[*] litres/second
[**] kiloPascal
Minimum fl ow [*]
0.20 l/s 0.14 l/s
0.25 l/s 0.18 l/s
0.31 l/s 0.22 l/s
0.38 l/s 0.26 l/s
Connecting the heat pump to the heating system
Max system pressure drop [**]
17
36.0 kPa
36.0 kPa
34.0 kPa
32.0 kPa
Flow (Q)