The FuelMizer® (SR501-OR) is a microprocessor-based control designed to regulate the supply water temperature of a single boiler, based on the outdoor temperature. The FuelMizer is a boiler reset control and switching relay in one unit; it is ideal for retrofit application, but may also be used in new installations. Its quality features include full outdoor boiler reset control: it can control the system or zone valve circulator, or it can override outdoor reset when DHW tank is calling. It’s easy to install and set and will not affect the boiler’s warranty. Front mounted LED lights offer full diagnostic information. The FuelMizer’s typical energy savings is about 14%, with some customers experiencing 30%.