split solar geyser systemThe ideal solar geyser system operates on the thermosyphon flow principle as it is simpler, cheaper and often more efficient.

However, this is not always possible for the following reasons:

  • It may not be possible to get the solar geyser water tank high enough above the collectors, because the roof pitch is low and the customer does not wish to use the mounting frame.
  • The customer may not wish to have the solar geyser water tank on the external roof for aesthetic reasons.

In these cases, an active circulation system – where a pump is used to circulate the water from the solar HWC at a lower position, up through the collector panels and back down to the solar geyser water tank – can be used. This allows the solar HWC to be “split” from, and installed lower than the collectors (i.e. the tank at ground level and possibly some distance from the collectors).


  • There is no ‘unsightly’ solar geyser water tank on the roof.
  • They can sometimes be retrofitted to use existing storage tanks.
  • There is less roof work.
  • The tank or collectors can be located in more accessible or appropriate locations.


  • They are more expensive than thermosyphon solar geyser systems, due to the pump and collector costs.
  • They require power to run the pump and temperature differential controller – this can be overcome by installing a photovoltaic module.
  • A more complex design is required.


Pre-heater solar geyserA pre-heater is a solar water heater system that heats the incoming water before it reaches the conventional water heater. If the incoming water is warmer, it takes less electricity to heat it to the regular hot water temperature. A pre-heater is more effective than connecting any other solar heater system.