The ProLine® 400/401 Series gas water heater is designed to deliver an economical performance that can lower your energy bills and also provide long-lasting value.Featuring a 40-gallon (nominal) tank and a 40,000 BTU gas burner, the XCRL-40 Standard Vent delivers a first hour rating of 67 gallons and a recovery rate of 41 gallons per hour. With an 0.59 Uniform Energy Factor, this water heater is not ENERGY STAR® certified. It carries a 10-year limited tank warranty, and meets Low NOx emission requirements.A. O. Smith’s ProLine® water heaters are residential products built to commercial-grade standards and are only available for purchase through professional wholesalers and contractors.