The TTS Synergy Series tankless rack solution features a turndown ratio of 66:1 that will provide more than 1,600 gallons of hot water per hour, yet is compact enough to fit through a standard mechanical room doorway. The standard package consists of an aluminum frame rack holding from two to six Noritz NCC199CDV Commercial Condensing Water Heaters with maximum inputs of 199,900 Btu/h and maximum flow rates of 11.1 gpm. Also included are the system controller, water and gas manifolds, expansion tank, breaker box with circuit breakers, digital pump controller with timer, surge protector, building recirculation pump and isolation valves — all pre-installed and pre-piped to the attached water heaters. The installer needs to make only a single connection apiece for the water, power, gas, vent, condensate drain and building-recirculation lines.