A method of making a titanium heating element for electric water heaters includes heating commercially pure titanium tubing to a specified temperature for a predetermined period of time. A resistance wire and magnesium dioxide powder may be positioned in the tubing prior to the annealing process. The outer surfaces of the titanium tube are exposed to the air during at least a portion of the annealing process, such that a layer of titanium dioxide develops on the outer surface of the titanium. The heating element is then formed into a loop or other suitable shape, and it is positioned inside a housing. The housing may include fittings to connect the water heater to the tubing of a pool, jetted tub, spa, hot tub or the like.