Pre-Installation
Greenstar 4000 – 6 720 891 162 (2020/09)
14
Sealed primary system - 3-way valve, cylinder and central heating
zone:
Typical Y-Plan example
• The cylinder return must be the last connection on the common
return pipe to prevent reverse circulation.
Fig. 8
3-way valve, cylinder and heating zone
[1]
Appliance
[2]
3-Way zone valve
[3]
Hot water cylinder
Optional integral diverter valve kit
The integral diverter valve kit is designed to operate on a sealed system
only. The appliance will require to fit a separate flow and return pipe from
the water cylinder to the wall mounting frame and terminate in 15mm
copper pipe.
Details for the connection of the integral diverter valve kit components
are found within the Installation Instructions for the kit.
Sealed primary system - Internal diverter valve kit:
• This appliance is designed to operate on a sealed system only. The
appliance will require a second flow and return pipe from the hot
water cylinder to the wall mounting frame and terminate in 15mm
copper pipe. The following system layouts show a simplified example
of the pipe configuration to the appliance.
Fig. 9
Example layout - Internal diverter valve kit
[1]
Appliance with internal diverter valve kit
[3]
Unvented hot water cylinder
Unvented cylinders
In all cases the cylinder manufacturer must be contacted for
confirmation their product is suitable for the installation layout shown in
figure 9.
Although it is accepted common practice to install 2-port motorised
valve in the primary flow pipe to the cylinder and wired to the dual-
thermostat supplied with the cylinder, it is possible to use the integral
diverter valve kit and not need the 2-port motorised valve to cut the flow
of heat to the cylinder to comply with Building Regulation Part G3.
• The integral diverter valve kit cylinder sensor must be used.
• The general layout (figure 9) can be used for unvented cylinders by
utilising the high limit thermal cut-out of the cylinder dual-thermostat
to interrupt the permanent live to the appliance, preventing any heat
being produced by the appliance.
Example layout with unvented cylinder & cylinder safety valve.
If required by the cylinder manufacturer to fit/use the cylinder safety
valve then this can also be carried out (figure 10) with the integral
diverter valve kit.
• The cylinder safety valve and dual-thermostat (control thermostat
and high limit thermal cut-out) are wired to interrupt the permanent
live to the appliance, preventing any heat being produced by the
appliance.
Fig. 10 Example layout - Internal diverter valve kit with unvented
cylinder and cylinder safety valve
[1]
Appliance with internal diverter valve kit
[2]
Cylinder safety valve (unvented cylinder)
[3]
Unvented hot water cylinder
1
2
3
0010021231-002
1
3
0010021286-002
1
3
2
0010021233-002
