The ProLine® Master 40-Gallon Ultra-Low NOx Atmospheric Vent Tall Natural Gas Water Heater delivers an efficient, reliable performance and features an innovative design that protects against accidental ignition of flammable vapors.

Featuring a 40-gallon (nominal) tank and a 40,000 BTU gas burner, the HUR-40 Atmospheric Vent delivers a first hour rating of 83 gallons and a recovery rate of 41 gallons per hour. It carries an 8-year limited tank warranty and meets Ultra-Low NOx emission requirements.

Environmentally-friendly insulation and factory-installed heat trap nipples reduce heat loss for maximum energy savings.

This ProLine® Master water heater is designed with A. O. Smith's superior commercial-grade tank protection. Advanced tank features include stainless steel CoreGard™ anode rod, Blue Diamond® glass lining and DynaClean™ automatic sediment-cleaning system, all designed to help protect the tank from the corrosive effects of water and extend the life of the water heater.

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.