Xtend elements address a number of issues with water heating and use around 25% less electricity to heat the same amount of water at the same rate.The PTC ceramic heating core matches power consumption to heat transfer for maximising efficiency. The PTC is encased in 316 stainless steel. This, combined with the low watt-density makes Xtend ideal in hard water areas. The lower watt-density reduces the speed of scale build up and the stainless steel does not degrade. As scale build up increases, heat transfer efficiency decreases. With a standard element, this leads to reduced efficiency and ultimately, element failure. Xtend elements reduce the power drawn to match the heat transfer. The nature of PTC enables this. The result is that the will heat more slowly, but not cost more to heat. Xtend elements can be removed and easily cleaned. Xtend elements is superior to normal elements if a geyser runs dry. They will draw minimal power, from time to time, until the issues is rectified. Then they will work as normal. Installing Xtend elements in your geyser makes it the perfect solution to use in conjunction with solar power systems. Most hot water is used at night, thus the current drawn from the batteries with Xtend elements will be less. A 2kW Xtend element is equivalent to a 3kW standard element and therefore best suited for a 150lt geyser. The thermostat should also be set 5 Degree less than required temperature.