Door insulator with safety plug

A water heater comprising:

• a tank defining a water chamber, the tank including an outer surface;
• a component coupled to the outer surface of the tank;
• a jacket surrounding the tank, the jacket including an opening providing access to the component;
• and
• a door assembly that includes a dam having an inner surface,
• wherein the inner surface of the dam seals against the outer surface of the tank when the door assembly closes the opening, the dam being positioned to protect the component during injection of insulating foam between the tank and the jacket.

A method for manufacturing a water heater, the method comprising:

• providing a tank defining a water chamber and including an outer surface;
• providing a component coupled to the outer surface of the tank;
• providing a jacket surrounding the tank and including an opening providing access to the component;
• providing a door assembly that includes a dam having an inner surface;
• sealing the inner surface of the dam against the outer surface of the tank;
• after sealing the inner surface, injecting foam between the tank and the jacket and around the dam to provide insulation between the tank and the jacket;
• and
• protecting the component from the injected foam with the dam.

A water heater comprising

• a tank defining a water chamber, the tank including an outer surface;
• an electrical component coupled to the outer surface of the tank, the electrical component extending from the outer surface of the tank;
• a jacket surrounding the tank, the jacket including an opening providing access to the electrical component;
• a dam which is located within the opening, and which includes interior walls defining a space containing the electrical component;
• insulating material located between the tank and the jacket and outside of the dam;
• and
• a door assembly that includes a door adapted to be mounted to the jacket, and a ceramic insulating cap that is attached to the door, that extends over the electrical component, and that engages the interior walls of the dam so that the ceramic insulating cap insulates the tank and rigidifies the dam.