INSTALLATION – SOLAR STORAGE TANK
27
TANK WATER SUPPLY
If the water heater is supplied with water from a tank supply and a minimum water supply pressure of 140 kPa
at the water heater cannot be achieved, then a pressure pump system must be installed to allow the gas
booster to achieve its rated flow and performance. 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.
RAINWATER COLLECTION SYSTEM
Before installing a closed circuit system, the installer should determine whether rainwater run-off from the roof
on which the solar collectors will be mounted, is collected in a rainwater tank. If the solar collectors are to be
installed on a section of roof which is part of a rainwater runoff collection system, then it is recommended this
section of roof and its gutter be isolated from the rainwater collection system. The gutter should be isolated to
a width greater than the solar collectors and pipe work and must have suitable drainage. The installer should
ensure in the event of a leak from the closed circuit, a rainwater tank cannot be contaminated with closed
circuit fluid.
The closed circuit fluid acts as an anti-freeze agent and rust inhibitor, is non-toxic to humans and is harmless
to the environment. However it does have an adverse effect on water stored in rainwater tanks. It will kill
microscopic algae typically present in rainwater tanks and cause an unpleasant odour to develop. This will
result in the rainwater tank having to be drained and cleaned.
The section of roof and gutter should be isolated from the rainwater collection system before the commissioning
of the solar water heater, so that any leak or spillage during commissioning does not make its way into the
rainwater tank.
The installer should discuss alternative options to suit the installation with the householder. Any alterations to
the roof drainage system must comply with the relevant building regulations, codes and Standards.
Refer to
on page 13 for additional information on what to do if a rainwater tank
does become contaminated with closed circuit fluid.
FREEZE PROTECTION
The water heater has a freeze protection system. The water heater, including the in-series gas booster, is not
suitable for installation in areas where the ambient temperature falls below -20°C (including wind chill factor).
The closed circuit fluid is an anti-freeze agent which, when mixed to the correct specification, can withstand
temperatures of -20°C before it may freeze.
Solar Circuit
To offer protection against freeze damage, the solar circuit must be installed with a continuous fall of a
minimum 5° (1 in 10 grade) in the pipe work from the solar collectors to the solar storage tank, with the full
length of the solar hot and solar cold pipes insulated and the system charged with correctly mixed closed circuit
fluid. The system has NO WARRANTY for freeze damage if there is not a continuous fall in the solar hot and
solar cold pipes or they are not insulated in accordance with the installation instructions or the closed circuit
fluid has been incorrectly mixed (refer to
on page 37).
The anti-freeze control of the solar circuit is designed so there is no closed circuit fluid in the solar collectors
or solar hot and solar cold pipes when the pump is off. The solar circuit only contains closed circuit fluid when
the pump is operating during periods of solar gain when heating is required. When the solar pump stops
operating, the closed circuit fluid drains back into the storage tank heat exchanger.
Gas Booster Water Heater
The in-series gas booster has a frost protection system. The frost protection system will protect the in-series
gas booster from damage by preventing ice forming in its waterways, in the event of freezing conditions
occurring.
The frost protection system will be rendered inoperable if electrical power is not available at the in-series gas
booster.
Pipe work to and from the in-series gas booster must be adequately insulated to prevent freezing. Refer to
AS/NZS 3500.4 for precautions to be taken for installations in frost prone areas.
Damage to the in-series gas booster caused by either the unavailability of power at the gas booster or freezing
of the pipe work to or from the gas booster is not covered under the Rheem warranty. Refer to
on page 4.
