33-1197 Solahart Owner‟s Manual – Thermosiphon Systems - Revision F –Jan. 12 3
Water Quality - Is It Suitable For The Solahart Water Heater?
Your Solahart water heater is suitable for use with water with a total dissolved solid content less than 1,000 ppm and for
which the total hardness does not exceed 200 ppm CaCO3. Water supplies having calcium hardness (CaCO3) and an
alkalinity in excess of 150 ppm should be treated by a softening process prior to use with this water heater to prevent
scaling and damage to the electric booster element.
A water analysis can be obtained from your water supply authority.
Period Of Reduced Usage Or Holidays
WARNING: IF THE WATER HEATER IS LEFT UNUSED FOR TWO WEEKS OR MORE,
FLAMMABLE HYDROGEN GAS MAY ACCUMULATE IN THE WATER CYLINDER.
To dissipate this gas safely, it is recommended that a sink hot tap be turned on for several minutes. Do not use a
dishwasher, clothes washer or other appliance for this purpose. During this procedure there must be no smoking, open
flames or any electrical appliance operating nearby. If hydrogen is discharged through the tap it will make an unusual sound
like air escaping.
‘Hartgard’ Solution –Freeze Protection
Solahart Closed Circuit Systems are protected against freezing or harsh water conditions by our exclusive „Hartgard‟ fluid.
„Hartgard‟ is a blue, non-toxic, propylene glycol fluid which, when mixed with water, provides the Heat Transfer Fluid
contained in the solar panels and the heat exchanger jacket around the tank. „Hartgard‟ is used to lower the freezing
temperature of the Heat Transfer Fluid and so provides protection against freezing (Note: for the correct % of Hartgard in
the Heat Transfer Fluid, refer to the section on Frost / Freeze Protection). „Hartgard‟ is a special food grade solution and is
the only solution permitted to be used in the closed circuit systems. Hartgard has been approved by the National Health and
Medical Research Council of Australia.
WARNING: SHOULD THE WATER FROM YOUR CLOSED CIRCUIT SERIES WATER HEATER
APPEAR BLUE, THEN THIS MAY INDICATE A LEAK OF „HARTGARD‟ FROM THE HEAT
EXCHANGE JACKET INTO THE POTABLE WATER.
Although ‘Hartgard‟ is of food-grade quality and not hazardous to health, the blue colour in the water does indicate a fault
and your Solahart dealer should be contacted to inspect the system.
Over-Temperature Protection System
The Closed Circuit Series solar water heaters have a means of controlling the maximum temperature of the water in the
storage tank. These systems may be installed with a „HartStat‟ valve located between the hot outlet of the collectors and the
inlet to the tank heat exchanger. This valve closes when the tank has reached a sufficiently high temperature, thereby
preventing further heat transfer to the tank, and thus limiting its temperature.
The Open Circuit Series systems may be installed with a „TRV‟ located between the cold inlet of the tank and the cold inlet
of the collectors. This valve restricts the flow through the collectors when the tank has reached a sufficiently high
temperature.
PR6 / PR200 Jacket Pressure Relief Valve
The Closed Circuit Series tank‟s heat exchange jacket has a pressure relief valve located in the vent pipe of the jacket. This
relief valve is to prevent over-pressurisation of the closed circuit either due to incorrect filling or abnormal operating
conditions. During the water heater's first summer season, fluid will discharge from the relief valve until the ideal closed
circuit fluid volume is established. Discharges from the valve after this time could indicate the water heater is not operating
efficiently. Under these circumstances contact your nearest Solahart dealer immediately. Do not attempt to service the water
heater yourself.
When operating in daylight, the heat exchange circuit will be pressurised and will contain a mixture of superheated water
and steam. Do not remove the PR6 / PR200 valve during operation as there may be a very high SCALDING risk present.
