INSTALLATION – SOLAR STORAGE TANK
26
TANK WATER SUPPLY
If the water heater is supplied with water from a tank supply and a minimum water supply pressure of 200 kPa
at the water heater cannot be achieved, then a pressure pump system must be installed to allow the collector
circuit system to operate. Care must be taken to avoid air locks. The cold water line from the supply tank should
be adequately sized and fitted with a full flow gate valve or ball valve.
HOT WATER DELIVERY
This water heater can deliver water at temperatures which can cause scalding.
It is necessary and we recommend that a temperature limiting device be fitted between the water heater and
the hot water outlets in any ablution and public areas such as a bathroom, ensuite or public amenities, to
reduce the risk of scalding. The installing plumber may have a legal obligation to ensure the installation of this
water heater meets the delivery water temperature requirements of AS/NZS 3500.4 so that scalding water
temperatures are not delivered to a bathroom, ensuite or other ablution or public area.
The temperature limiting device used with this solar water heater should be capable of receiving a hot water
supply temperature of up to 99°C and have a specified
‘minimum temperature differential’ between the hot
water inlet and the tempered water outlet of no greater than 10°C. Refer to the specifications of the temperature
limiting device.
Where a temperature limiting device is installed adjacent to the solar water heater, the cold water line to the
temperature limiting device can be branched off the cold water line either before or after the isolation valve
and pressure limiting valve to the solar storage tank, but it
MUST BE
before the non-return valve. If an
expansion control valve is required, it must always be installed after the non-return valve and be the last valve
prior to the solar storage tank.
Warning:
A non-return valve
MUST BE
installed on the cold water line to the solar storage tank
AFTER
the cold water branch to a temperature limiting device. Due to the higher water temperatures generated under
certain conditions in the solar collectors of this solar water heater, an additional effective back-flow prevention
device also should be used as an extra safeguard. Valve manufacturer RMC recommends Dual Check Valve
model N7155, as being suitable for this application.
If a combination isolation valve and non-return valve (duo or trio valve) is installed on the cold water line to the
solar water heater and the cold water line to the temperature limiting device branches off after this valve, then
a second non-return valve must be installed between the cold water branch and the solar storage tank. Due
to the higher water temperatures generated under certain conditions in the solar collectors of this solar water
heater, an effective back-flow prevention device should be used as the second non-return valve as an extra
safeguard. Valve manufacturer RMC recommends Dual Check Valve model N7155, as being suitable for this
application.
If a pressure limiting valve is installed on the cold water line to the solar water heater and the cold water line
to a temperature limiting device branches off before this valve or from another cold water line in the premises,
then a pressure limiting valve of an equal pressure setting may be required prior to the temperature limiting
device.
Two Temperature Zones Using a Temperature Limiting Device
LEGEND