[Heathkit] Re Hot Water 101?

[Duane Fischer, W8DBF]

Hi All,

My ever curious mind knows that this list has one incredible collection of 
radio hobbyists with nothing short of a tremendous pool of knowledge to dip 
facts from, and if an answer is to be had, here it will be found!

Can any of you tell me how, or why, the Heathkit "HW" product line came by 
the "Hot Water" designation?

Thanks!

Duane Fischer, W8DBF