The Rinnai 26L Solar Boost Model S26N70 is designed for usage within the Sunmaster and Prestige solar thermal systems. This intelligent model is specifically designed for solar boosting, and will automatically work to maintain a temperature of 70C in your hot water system. It is factory set at this temperature but can be adjusted to your needs through a simple and easy procedure that is outlined in an instruction booklet provided with each unit. The boiler automatically turns off if overheating occurs, ensuring safety and peace of mind when using your hot water system.