Our most popular steam-to-water package, the WaterWizard features dedicated sub-cooling capabilities for enhanced operating efficiency. AERCO's unique feed-forward monitoring system and fully modulating control valves maintain +/-4°F water temperatures under the diversified load patterns of commercial domestic hot water applications. Performing with 90%-99% thermal efficiency, the unique 2-pass helical coil heat exchanger design of these single wall heaters is self-descaling and produces sub-cooled condensate (< 160°F ) to preserve condensate return pump life. All units are compatible with low or high steam pressures and do not require a storage tank, trap or associated maintenance.