a spa heater includes a heater element having a single outer wall with indentations near each end for receiving clips for positioning the heater element . the indentations are preferably stamped or formed by some other method which does not weaken the outer wall and the heater element is retained by use of the clips in the indentations . incorporation of the indentations and the clips allows use of a single thin outer wall thereby reducing cost . the heater element is held and sealed by a combination of o - rings , stepped washers , snap rings clips , and caps . an electrical connection may be made using ring type wire ends residing under the caps or by connecting to posts extending from the ends of the heater element . the heater element is preferably a spiral heater element and a titanium outer wall may be used to resist corrosion and increases heater element life .