Domestic Solar Water Heaters/Solar Geysers - Thermosiphon closed loop systems are designed for heating water from solar energy, operating on the thermosiphon principle. The thermosiphon is a passive design, which allows heat transfer using natural convection ideally in a vertical heating system. Solar fluid (Water + Glycol) remains in closed loop. After getting heated in the solar panel it rises to outer jacket of tank and transfers the heat to the stored water in the tank before finally returning to lower side of the solar panel for renewed absorbtion of solar energy. The advantage is that it avoids using a conventional pump, which keeps the complexity and cost of a thermosiphon system low and at the same time ensure that the panel tubes always remain clean inside and for efficient heat transfer.