Thread resurrection!
So hot water that runs through a boiler picks up more chemicals? Since we're boiling water does it even matter? I thought boiling purifies water.

Anyway, I always use the hot water thinking it can come to a boil a minute faster. Cooking rice and beans takes some time.
Running water through pipes and containers in general causes it to acquire new dissolved contents, yeah, naturally. And no, of course boiling it doesn't purify all of those contents out of it, unless you run it through a distilling device also.
Think about it this way -- suppose you run water through a mile of copper piping. It will pick up trace amounts of copper (which is solid at room temp, obviously). It also has some dissolved substances in it that are gases at room temperature, like fluorine. If you boil it, you might get rid of things that are gaseous at the boiling temperature, but how are you going to get rid of the copper? The boiling temperature is 100C... copper
melts at over 1000C. You're not going to turn it into a gas. How is it going to escape from the boiling water?
That's the general idea... it's those solid substances in the water (calling them "chemicals" doesn't really mean anything... the water
itself is a "chemical") that you acquire in different conveyances and which can affect the taste of the water.
It's going to depend on your taste sensitivities, though, and also the hardware in your home.
It is funny that this thread came up, because I did start letting the cold water run for a few moments before filling my coffee pot. I honestly don't notice a huge difference, though.
