15
Hot Water Redundancy
If this solar water heater is to be used where an uninterrupted hot water supply is necessary for the
application or business, then there should be redundancy within the hot water system design. This should
ensure the continuity of hot water supply in the event that this solar water heater was to become inoperable
for any reason. We recommend you provide advice to the solar water heater owner about their needs and
building backup redundancy into the hot water supply system.
Water Supplies
Mains Water Supply
Where the mains water supply pressure exceeds that shown in the table below, an approved pressure
limiting valve is required and should be fitted after the stop cock and before the non return valve as shown in
the
“Cold Water Supply Plumbing Arrangement” diagram on page 21.
Model
SG165, SG260, SG325
&
SG415
Pressure temperature relief valve setting
1000 kPa
Expansion control valve (ECV) setting *
850 kPa
Minimum mains supply pressure
200 kPa
Maximum mains supply pressure
With ECV
680 kPa
Without ECV
800 kPa
* Expansion control valve not supplied with solar water heater.
Tank Water Supply
If the solar water heater is supplied with water from a tank supply and a pressure pump system is not
installed, then the bottom of the supply tank must be at least 1 m above the highest point of the premises hot
water plumbing system, including the solar storage cylinder. Care must be taken to avoid air locks. The cold
water supply line to the solar water heater must be adequately sized and fitted with an approved full flow
gate valve or ball valve and non return valve.
If the solar water heater is supplied with water from a tank supply and a minimum water supply pressure of
200 kPa at the solar storage cylinder inlet cannot be achieved, then a pressure pump system must be
installed to ensure the minimum mains supply pressure is provided and maintained. Care must be taken to
avoid air locks. The cold water line from the supply tank should be adequately sized and fitted with an
approved full flow gate valve or ball valve and non return valve.
Water Supply Chemistry
Bad water can have a detrimental effect on solar water heater operation, components and life expectancy
and may affect warranty. Refer to “Water Chemistry” on page 9 for more information. Also refer to “Spring,
Dam, Bore & River Water Supplies” on page 11.
