Low-pressure geyser technical specifications


If you want to save money on your electricity bill start with a solar geyser. The following guide will help you decide whether a low pressure geyser option would suit your needs.

Difference between low and high pressure

Municipal water supply is usually between 1bar and 5bar (depending on location and time of day).

High pressure solar geysers can be connected directly to a high pressure water supply such as municipal water supply without a pressure reducing valve. This will allow integration to an existing plumbing system. Hot water pressure at the taps or shower head will be similar to the cold water pressure and will allow higher flow rates.

Low pressure solar geysers are open to atmosphere, hence the hot water pressure will be equal to the static water head (height of which geyser is mounted). The low pressure solar geyser can be used on municipal water supply if a pressure reducing valve is used on the cold water supply to the plumbing system (this will allow mixer taps and showers to have balanced water pressure between hot and cold water). The auxiliary tank acts as a pressure reducing valve on the hot water side.

Low Pressure Solar Geyser

The low pressure geyser requires installation on top of your roof. Typically characterized by vacuum glass tubes connected directly into a tank with a small auxiliary tank on top of it. The evacuated glass tubes are filled with water and exposed to sun, thus heating up the water in the glass tubes.

Sizing your geyser to your needs:

The standard geyser sizes are 100L, 150L, and 200l.

The number of people inside the home will determine the size of the geyser, we work on about 50L per person inside the home.

You can connect two geysers in series which works well if you are looking for a geyser larger than 200L.

Available models:

Model Stainless steel Stainless steel Stainless steel
Volume 100L 150L 200L
Qty. of tubes 10 15 20
Tube 58x1800x2 mm 58x1800x2 mm 58x1800x2 mm
Exterior Tank Material

0.35mm Stainless Steel

0.35mm Stainless Steel Sheet

0.35mm Stainless Steel Sheet

Interior Tank Material 0.35mm SUS304 Stainless Steel 0.35mm SUS304 Stainless Steel 0.35mm SUS304 Stainless Steel
Outer Tank Diameter 470mm 470mm 470mm
Insulation 55mm Polyurethane Foam 55mm Polyurethane Foam 55mm Polyurethane Foam
Stand Flat/pitched roof stand (1.5mm galvanized and painted) Flat/pitched roof stand (1.5mm galvanized and painted) Flat/pitched roof stand (1.5mm galvanized and painted)


Geyser kits include

  • 100L, 0.31mm SUS304 s/steel tank with stainless steel outer shell
  • Flat/pitched roof stand (1.5mm galvanized and painted)
  • 10 x 2mm vacuum tubes (designed for 38mm diameter hail) and
  • Stainless steel auxiliary tank

Optional electric backup system:

All models can accommodate a standard 32 mm screw-in South African electric element with pocket. It can be controlled with either a thermostat or an SR609 programmable controller.

The SR609 is a programmable electronic control panel. The features include:

  • The display of the water temperature inside the tank that is measured by a probe that fits inside the pocket of the element.
  • It can be set to heat the water in the tank electrically in three cycles of time and temperatures.
  • Default: if the water is cooler than 54oC between 4 and 5 am, the water will be heated to 60oC. The same happens between 5 and 10 pm again.
  • A manual button raises the temperature up to the programmed temperature (usually 60oC), whenever needed.
  • There is a battery backup, so it will not forget its settings.

Why choose low pressure

  • Cost-effective system that works very well
  • Simple and has no moving parts
  • Due to lower pressure and stress on the tank, it has a longer life expectancy.
  • Low-maintenance
  • Highly effective

If you want a cost-effective system that works very well the low-pressure system is a good choice. Keep the flow in mind, especially if there are 15mm plumbing pipes between the geyser and the bath, and when you want a 22mm flow at the tap. Some one-lever mixer taps will restrict flow substantially. Two-knob mixers do not cause flow problems easily.

Installation instructions and additional information available at Technical Support.