McDonnell & Miller’s RBT-3000 Low Water Cut-Off and Fuel Economizer is designed to maximize fuel efficiency and provide protection for hydronic heating systems. The intelligent controls built into the RBT-3000 automatically adjust water temperature based on heat load and without the need for an outdoor sensor. The energy management system reduces fuel/electricity consumption by 10% to 20%. All McDonnell & Miller electronic low-water cut-offs provide the added protection of an exclusive self-cleaning probe, which eliminates the need for probe