The AT Series Electric Boiler is 100% efficient. No wasted energy. This means no fossil fuel and no chimney. You save on fuel delivery, storage tank (including: tank maintenance, repairs and insurance), and there is no chimney maintenance or repair costs! Ideal for home heating systems, radiant system applications requiring special temperature settings and for use as a back-up heat source for solar and heat pump applications. Heating systems that require both a high water temperature in combination with a low water temperature are no problem for the AT Series boiler. The advanced microprocessor control allows the installer to have two different temperature settings for a wide range of applications.