Specifications

ABOUT YOUR WATER HEATER
5
GAS BOOSTING OPERATION
Water stored in the solar storage tank passes through the in-series gas booster when a hot tap is opened.
The in-series gas booster is for heating the water at times of low solar energy gain, such as during cloudy or
rainy weather, or during colder months.
Solar heated water can reach temperatures up to 75°C in the solar storage tank. When the solar heated
water temperature is 58°C or above, the in-series gas booster will not boost the water temperature. When
the solar heated water temperature is below 58°C, the gas burners ignite to provide immediate heating of the
water to its preset outlet temperature setting. The heat produced by the burner is transferred to the water
through the heat exchanger. The water is heated to a constant temperature by the automatic adjustment of
the gas supply to the burner to suit the water flow rate. The gas burners extinguish when the hot tap is
closed.
If another type of in-series booster water heater is used and the solar heated water temperature is above its
thermostat setting, the water heater will not boost the water temperature. When the solar heated water
temperature is below the thermostat setting of the water heater, the booster will operate to heat the water.
MAINS PRESSURE
The water heater is designed to operate at mains pressure by connecting directly to the mains water supply.
If the mains supply pressure in your area exceeds that shown on page 24, a pressure limiting valve must be
fitted. The supply pressure should be greater than 350 kPa for true mains pressure operation to be achieved.
The supply pressure should be greater than 140 kPa for the rated flow and performance of a Vulcan in-series
gas booster to be achieved.
REDUCED HOT WATER FLOW WHEN HEAT EXCHANGER IS COLD
At a cold start-up, i.e. when the in-line gas booster has not operated for some time (which is most often first
thing in the morning), the initial flow of hot water may be reduced for a period of 5-10 seconds while the heat
exchanger warms up. This is both an energy and water saving feature of this water heater. Once the
heat exchanger has warmed up the hot water flow will increase and remain at normal flow levels. This
feature will only occur at a cold start-up and not when the heat exchanger is already warm from a recent use
of hot water.
HOW HOT SHOULD THE WATER BE?
The solar control unit will circulate the closed circuit fluid through the solar
collector until a temperature of approximately 75°C is reached in the solar
storage tank. During periods of low solar energy gain, the continuous flow
in-series gas booster will boost the water temperature automatically to its
preset outlet temperature setting, or to the temperature setting of another
type of in-series booster water heater.
The factory preset outlet temperature setting of the in-series gas booster is:
244 620 60°C
244 627 60°C
Note: The preset outlet booster temperature setting of the continuous flow
in-series gas booster cannot be adjusted by the householder. The setting
can only be adjusted by the installer, Rheem Service or their nearest
Accredited Service Agent.
Note: AS 3498 requires that a water heater provides the means to inhibit the growth of Legionella bacteria in
potable water. If this water heater is installed with an continuous flow in-series gas booster, then this
requirement of AS 3498 can be satisfied provided the booster is energised, its preset outlet temperature
setting is 70°C or higher and a remote temperature controller is not used.
If this water heater is installed with an in-series storage booster, then this requirement of AS 3498 can be
satisfied provided the storage booster is energised and its thermostat setting is 60°C or higher.
Warning: Temperature controllers must not be fitted to the in-series booster as part of a solar water
heater system because water at a temperature much higher than the controller setting can be delivered.
typical maximum
temperature from solar
gain
maximum
recommended supply
temperature to
bathrooms and
ensuites