Compact, resilient, high-performance. The Hubbell Synergy Hydro BWX is a fully packaged semi-instantaneous indirect water heater. It uses boiler water or high temperature hot water to heat potable water. Semi-instantaneous design reduces standby heat loss and operating costs. ASME-rated pressure vessel and T&P relief valve. Small footprint for compact spaces. Available in vertical or horizontal orientations. Simplified installation with factory selected and sized boiler water control valve.