You may have had the wonderful experience of starting a
nice, hot shower, only to find that somebody has mostly drained the hot water
heater tank. This leaves you desperately turning the tap to more and more hot water while the shower gets
cooler and cooler. You lather, rinse,
(no time for repeat) with feverish speed, but eventually wind up rinsing off in
lukewarm (or ice-cold) water. If so,
this post is for you.