Solar Pre-Heat systems

Make hot water while the sun shines.

Our solar pre-heat systems can be used in conjunction with any Rinnai water heating unit. By combining energy from the sun with highly efficient gas hot water heating, considerable savings on the running costs associated with producing hot water can be achieved. Using solar energy to pre-heat commercial gas and electric boosted hot water systems reduces energy consumption, as well as significantly reducing CO2 emissions.

Reduce Carbon footprint, save on energy costs

Stainless Steel storage tanks

High efficiency solar collectors

  • Stainless steel storage tanks for longer life
  • Storage sizes of 250 and 315 litres for ease of installation
  • High grade insulation to minimise heat loss
  • Highly efficient flat plate or evacuated tube collectors
  • A dedicated, state of the art, controller to circulate the water through the collectors

Suitable Applications include:

  • Large apartment blocks
  • Large Hotels
  • Hospitals
  • Nursing Homes
  • Aged Care Facilites

Save with STCs Rebates*

All Rinnai solar preheat systems are performance tested and modeled as a complete system. The energy savings are awarded STCs and can offer substantial rebates for commercial solar installations.

Save on Running Costs

Common practice is to select a solar pre-heat system to contribute around 50% of the annual energy required to heat an average day’s hot water. This works out to almost a 100% solar contribution in summer (depending on solar zone). These factors in conjunction with government incentives (where available) make solar pre-heating a shrewd and responsible investment.

The product information on this website (comprising product brochures, warranty information, installation manuals, diagrams, specifications and representations) relates to current products. This information may be different for superseded products. For superseded products please contact Rinnai to confirm product information.


  • Why use a solar (thermal) hot water system?

    Why use a solar (thermal) hot water system?

    Installing a solar hot water system has great benefits especially when replacing an electric storage tank. It can potentially reduce electricity consumption, running costs and environmental impact by 2/3rds.

    40% of a typical households electricity is used for heating water. Therefore a solar water heater can potentially reduce the overall electricity use by 25%.

    Australian electricity is predominantly generated using non renewable and dirty coal fired power stations. As well as electricity they produce carbon dioxide emissions, ash, particles and waste heat, while consuming vast quantities of water and non renewable coal.

    Rinnai solar hot water systems reduce the need for electricity and are part of many major energy reduction programs. Solar hot water systems also offset electricity just when it is needed most: Summer - as that is when air conditioners are running, loading up the electricity network.

  • How do I size a solar hot water system?

    How do I size a solar hot water system?

    The storage tank should hold a one days supply of hot water and have enough capacity to store the amount of solar energy collected by the solar collectors. Once the tank size is chosen to match household hot water use, the number of solar collectors is matched to the tank.

    For help with selection contact one of our licensed dealers or alternatively visit our store locator.

  • What is a solar hot water system?

    What is a solar hot water system?

    A typical solar hot water system is made up of solar collectors, a storage tank, a gas or electric booster and a solar controller and pump for split systems.

    There are two types of systems available

    1. Close Coupled systems
    2. Split systems

    Close Coupled systems have the storage tank above the solar collectors all located together on the roof. Close Coupled systems rely on thermosyphon to operate: cold water from the bottom of the tank falls to the inlet at the bottom of the solar collectors. The water is heated by the sun, rising up through the solar collector and back into the middle and top of the tank.

    Split systems have the storage cylinder located on the ground and the solar collectors located on the roof. Split systems use a solar controller and pump to transfer cold water from the tank to the solar collectors to be heated and returned to the middle or top of the tank. The solar controller compares the temperature of the water in the solar collector to that in the tank. When the collector is hotter than the tank the pump is switched on, transferring the solar heated water to the tank.

  • What is a solar collector?

    What is a solar collector?

    The solar collector is the most important component within the system as it absorbs the energy from the Sun and heats the water. Collectors are generally made up of a combination of:-

    • A glass surface (flat on a flat plate collector or round for evacuated tube collectors)
    • Tubes containing a fluid that is to be heated by solar energy
    • Heat absorbing surface / fins attached to the tubes
    • A treated surface on the absorber to capture and retain solar radiation
    • A casing / vacuum to retain heat
    • Pipework to enable the transfer of solar energy to the storage tank

    The solar collectors are roof mounted and ideally face North when installed in Australia. Facing East or preferably West is OK, but a reduced amount of solar energy will be collected.

    Avoid having the collectors shaded by adjacent buildings, structures and trees.

  • What is the difference between Solar Thermal Collectors and PV Panels?

    What is the difference between Solar Thermal Collectors and PV Panels?

    They are separate solar energy collection technologies.

    • Solar (thermal) hot water systems convert radiant energy into hot water.
    • Photovoltaic (PV) solar converts radiant energy into electricity.
  • Where to buy?

    Where to buy?

    You can use the store locator on our website to find your closest store.

  • How do I contact Rinnai?

    How do I contact Rinnai?

    You can contact us at 1300 555 545 or email us using the “contact us” form on our website.

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