O-ring seals for spa heater element

A water heater comprising:

• a heater housing having a housing wall;
• a heater housing inlet in the housing wall for allowing a flow of water to enter the heater housing;
• a heater housing interior of the housing wall for allowing the flow of water to pass through the heater housing;
• a heater housing exterior of the housing wall opposite the heater housing interior;
• a heater housing outlet in the housing wall for allowing the flow of water to exit the heater housing;
• a heater element having a heating portion, a first end and a second end, the heating portion residing in the heater housing interior and the ends passing through the housing wall, the heater element comprising:
• a titanium outer wall;
• an electrically conductive wire residing inside the titanium outer wall and spaced away from contact with the titanium outer wall;
• and
• a heat conducting dielectric insulation filling a space between the electrically conductive wire and the outer wall;
• heater element passages reaching through the heater housing wall, wherein the heater element ends pass through the heater element passages;
• indented seats at outside ends of the heater element passages;
• O-ring seals residing in direct contact with the heater element ends outside the heater housing exterior;
• and
• caps residing over the O-ring seals, the O-ring seals sandwiched between the caps and the indented seats in the housing wall for containing the flow of water in the heater housing interior.

A method for attaching a heater element to a heater housing, the method comprising:

• inserting two ends of the heater element through heater element passages in the heater housing from the inside to the outside;
• sliding O-rings over the heater element ends;
• and
• tightening caps over the O-rings to sandwich the O-rings to seal the heater element passages against water leaking from the heater.