This natural gas water heater is a qualified water heater engineered for superior efficiency and to deliver a higher energy factor (EF) to meet the latest Energy Star qualifications. State-of-the-art gas control with advanced self-diagnostics for quick and easy servicing. • Flammable vapour sensor detects presence of flammable vapours and automatically disables the unit preventing their ignition, only flammable vapour sensor in the industry that is protected from contaminants. •Robust air intake snorkel inhibits flammable vapours from entering the sealed combustion chamber, Relocated T&P and drain valve for ease of installation and serviceability. All units can be vented horizontally through the wall or vertically through the roof with plastic venting pipe certified for gas-fired appliances. Capacity: 151L (40 Gallons).