Page 18
Page 19
Schematic Solar Direct System
Solar Pumping Station
Solar Panel
Expansion
Vessel
Solar
Controller
Motorised Valve
Energy cut-out
(Not supplied)
Mixed HW out
Mains CW in
Figure 1: Cold port of the blending valve connected to mains supply
NOT ALLOWED
Mixed HW out
Mains CW in
Figure 3: Cold port of the blending valve connected to mains supply
to the vessel after the inlet control group
Balanced cold feed
Mixed HW out
Mains CW in
Balanced cold feed
Non-Return Valve (must be fitted)
Figure 2: Cold port of the blending valve connected to balanced cold
supply - NON-RETURN VALVE MUST BE FITTED
All components in a solar primary system must
be marked or identifiable in such a way that
their design pressure and temperature can be
readily determined.
A pressure relief valve to control the risk of
over-pressure in system components should
be fitted. A termination from a pressure relief
valve should minimise the risk of damage to
persons or materials. Suitable locations are
into a high temperature receptacle, an internal
gully or externally at ground level. High level
termination from walls or on roofs could cause
injury to people or animals below if the valve
were to release scalding water and steam.
The pipe leading to the safety device and the
collector should be of rigid and non-deformable
construction, without any possibility of
restriction or closure by any other fitted
component.
A more detailed diagram of our recommended
arrangement for a typical solar system is shown
on page 20.
This provides all the necessary controls and
safety devices necessary for the solar system i.e.
the two port zone valve is wired as an energy
cut out and the pump/valve will only allow heat
transfer as required under control of the solar
controller.
The solar pocket provided accommodates an
8mm diameter sensor which, with the sensor
located in the solar collector (or in the flow
pipe immediately adjacent to the collector),
will provide the information required by the
solar controller.
Note: If the motorised valve is not used then
any factory built hydraulic station for solar
use MUST be fitted with suitable non-return
valves in both flow and return pipes to
prevent gravity circulation when the pump
is not running.
If there is a possibility of the solar controller that
you install causing the cylinder temperature to
exceed 80°C, under normal working conditions,
then a Solar tempering valve must be fitted to
the domestic hot water outlet of the cylinder.
This must limit the hot water temperature to a
maximum of 60°C.(ref building regulations part
G3 3.63). This product can be supplied from
Gledhill part number XC007 which has a inlet
temperature limit of 100°C. Suitable plumbing
configurations for installing this valve are
shown on page 19 of this manual. NB. Any fitted
Overheat thermostats may require resetting
in the winter months to enable backup heat
sources to heat the cylinder.
Schematic Solar Indirect System
Solar Pumping Station
Solar Panel
Expansion
Vessel
Solar
Controller
Motorised Valve
Energy cut-out
(Not supplied)
Motorised Valve
Energy cut-out
(Not supplied)
Fitting Blending Valves To The Unvented
StainlessLite Plus Appliances
When fitting a blending valve to the unvented
appliances, it is important that the installation
does not contravene the G3, WRC and Health
and Safety directives or the manufacturers
recommendations. If this is the case, then
the warranty should be null & void. The key
requirements to comply with these regulations
are: -
1. Any fitting or material in contact with
potable water (e.g. a blending valve) must
be approved by WRC or an equivalent body.
2. Connections or wiring arrangements must
not bypass any safety devices.
3. Any expansion due to heating must not be
allowed to expand back into the cold mains.
4. The settings of any safety devices must not
be tampered with or adjusted.
The diagrams opposite shows how the
blending valve can be piped onsite.
Figure 1 shows the cold water port of the
blending valve connected to the mains cold
water supply before the inlet control group.
This arrangement is completely unacceptable
and illegal because: -
• the water is allowed to expand in to mains
cold water supply.
• the vessel will be charged to the incoming
mains supply which may be considerably
higher than the working pressure of the
vessel.
If this arrangement is used then the Gledhill
warrant will not be valid.
Figure 2 shows the cold water port of the
blending valve connected to the balanced
cold water outlet. This arrangement will only
be acceptable if a WRAS approved non-return
valve is fitted, otherwise: -
• during the heating cycle, the water will
expand back into the mains supply, as the
regulating valve must not be relied upon
to act as a check valve under all operating
conditions.
• depending upon the characteristics of the
blending valve, hot water may also flow from
the balanced cold water taps.
Figure 3 shows the cold port of the blending
valve connected to the cold water supply to the
vessel after the inlet control group. This should
be the preferred method. It is recommended
that the installer should ensure that there is no
gravity circulation in the pipework connected to
the cold port. If necessary, this can be achieved
by fitting a non-return valve or using a thermal
trap.
INSTALLATION
INSTALLATION
INSTALLATION
INSTALLATION
✗
