Short video by Tom Scott on the subject for those interested. https://youtu.be/HfHgUu_8KgA https://youtu.be/HfHgUu_8KgA tldw; Older homes in the UK had a wate

Short video by Tom Scott on the subject for those interested. https://youtu.be/HfHgUu_8KgA https://youtu.be/HfHgUu_8KgA tldw; Older homes in the UK had a water storage tank in the roof space that fed the water heating tank. This couldn't be classified as drinking water so wasn't allowed to be combined with the safe mains water that fed the cold tap. These days modern houses mostly use combi-boilers with no storage tank, so mostly both hot and cold are drinkable and it's not an issue. But preferences still lean towards the separate taps.