I wouldn't go so far as to say that hot water is one of the everyday things you don't really need but my hot water's been down for about a week now, and I've barely missed it.  I hasten to add that my shower's still working, electric powered, just that the tank in the cubby hole that heats water for washing dishes and hands has decided to take a break.  This has happened before; I turned if off for a few days and when I switched it back on, it came back to life.  I'm less confident of that happening again, so I may at some point soon get round to telling my landlord.  Thing is, I don't really need the hot water, as evidenced by the fact that here I am, hygienic and fully functional, without it.  No doubt doing without for a little longer will keep the energy bill down, too.  Just a thought.