gledhill Stainless Lite HP SOL Indirect 180-400 litres Design, Installation & Servicing Instructions page 19

• Sealed heating system
A heat pump selected must be suitable for use in a sealed heating system which
may have working pressure of up to 3.0bar and it must be fi tted with an overheat
temperature cut-out device.
Unvented (i.e. sealed primary circuits may be fi lled or replenished by means of a
temporary connection between the circuit and a water supply pipe provided a
WRC 'Listed' double check valve and fi lling loop or some other no less eff ective
backfl ow prevention device is permanently connected at the inlet to the circuit
and the temporary connection is removed after use.
Alternatively, a CA device can be used which will allow the system to be permanently
connected to the cold mains supply. The primary system can then be topped up,
Stainless Lite HP system configuration with solar thermal heating system
Heat pump
Solar Heating System
Stainless Lite HP SOL is suitable for use with combined heat pump and solar thermal
heating systems. All components in a solar primary circuit must be marked or identifi ed
in such a way that their design pressure and temperature can be readily determined
A safety device (pressure relief valve) to control the risk of over-pressure in system
components should be fi tted. A termination from a safety pressure device should
minimise the risk of damage to persons or materials. Suitable locations are a high
temperature receptacle, an internal gully or else issue 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 disclosure by any
other fi tted component. A more detailed diagram of our recommended arrangement
for a typical solar system is shown on page 15.
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 pocket provided for the Dual Thermostat also includes the facility to accommodate
an 8mm diameter sensor which, with the sensor located in the solar collector (or in
the fl ow pipe immediately adjacent to the collector), will provide the information
required by the solar controller.
Central heating zone valve
Hot water zone valve
System pump
Primary circuit
sealed system kit
PRV
Page 19
INSTALLATION
when required, in the same way as an open
vented system fi tted with an F&E cistern.
• Open vented heating system
It is essential that the primary circuit
between the boiler and the Stainless Lite is
pumped and that the cold feed and open
vent connections are positioned to prevent
pump over into the feed and expansion
cistern and to ensure that the open vent is
correctly sized. A typical arrangement of the
open vented system is shown in diagram
opposite.
PRV
Expansion
vessel
Solar
pumping
station
Solar circuit
zone valve
Central heating
flow and return
Note: If the motorised valve is not used then
any factory built hydraulic station for solar
use MUST be fi tted 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 fi tted 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 12 of this manual. NB.
Overheat thermostats may require resetting if
the solar thermal heat source raises the cylinder
temperature above 85°C.
INSTALLATION