There are two things that American visitors to Britain complain about. The first is having separate hot and cold taps on hand basins rather than a mixer tap. So pressing is this problem that the Wall Street Journal ran an article about it and Boris Johnson felt obliged to issue a statement saying that British plumbing “is an incentive to get it over and done with and not waste water”.
The second is the lack of ice in the hospitality trade. When one orders tap water in a restaurant it is, more often than not, warm. Most pubs still use a bucket full of partially melted ice for making gin and tonics. Americans are baffled by this. They have had a regular supply of ice since the 19th century. They would harvest ice in the winter and store it in specially designed ice boxes to keep it frozen.