Residential natural gas-fired power with vent water heater, FVIR compliant. Glass insulated inner tank with 2"eco-friendly Greenfoam. Equipped with a high efficiency burner of 40,000BTU with a flammable vapour sensor. Silicon nitride ingnitor, factory T and P relief valve, a brass drain valve, 3/4" N.P.T di-electric plumbing connections. 6-year limited warranty against inner tank leakage.