Since 1997, Thrush Co Inc. has been a designer & manufacturer of hydronic & HVAC products. Our Products include heat exchangers, the Aar-O-Vent air eliminator (patented design), Hot-Pak (semi-instantaneous hot water heate......Since 1997, Thrush Co Inc. has been a designer & manufacturer of hydronic & HVAC products. Our Products include heat exchangers, the Aar-O-Vent air eliminator (patented design), Hot-Pak (semi-instantaneous hot water heater), replacement tube bundles, tank heater assemblies, variable speed pressurizers, single and duplex constant speed boosters, air separators, flow guides (suction diffusers), pumps, circulators, valves, air vents, tanks, engineered heat transfer package systems, engineered frame mounted booster systems (constant and variable speed).