Hot water problem ... again!

I'm having hot water issue ... again. I don't get this, every single house that I've lived in London has had hot water issue. I must have offended the hot water God ... darn it.

I've lived in Sydney for over 10 years and had 1 issue with hot water, what is it with hot water installation in London? Or do I carry that much antipodean radiation that has damaging effect on hot water boilers in London?