Why Britain Uses Separate Hot and Cold Taps
Why Britain Uses Separate Hot and Cold Taps on HackerTube: recommended by 2 Hacker News commenters across 2 separate months, 2015–2025.
Tom Scott explains why Britain historically has separate hot and cold taps rather than mixer taps, tracing it to how water was stored in tanks. He notes why the hot tap is not safe to drink from.
What HN commenters said
8 Hacker News comments link this video. Each one links back to its thread.
SimonPStevensMar 2021Recommends
Short video by Tom Scott on the subject for those interested. ▶ this video 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.
in “Rents for the rich are going down, rents for the poor are going up. Why?” · View on HN
rogerbinnsMar 2015Recommends
It makes a lot of sense having them separate. Tom Scott explains ▶ this video Here in California showers and much other plumbing are required to have backflow valves so that hot and cold don't cross contaminate.
in “Britain's housing crisis is a human disaster” · View on HN
throw0101dApr 2025Cites it
Obligatory Tom Scott video on the topic: * [link] Bonus: "Why Britain Uses Separate Hot and Cold Taps": * ▶ this video
in “BS 1363 British Plugs and Sockets” · View on HN
croteSep 2023Cites it
That's because it is primarily a historical artifact[0]. Most modern plumbing heats water on-demand, which pretty much entirely avoids the risk of storage tank contamination or Legionella. [0]: ▶ this video
in “Lead poisoning causes far more death, IQ loss than thought: study” · View on HN
WirelessGigabitFeb 2023Cites it
Mandatory Giphy: [link] Also mandatory explanation why UK historically has had 2 taps: ▶ this video Which in the end is understandable. It's outdated. What isn't understandable is having the light switch OUTSIDE of the friggin' restroom.
in “A manifesto on shower temperature control” · View on HN
cyounkinsJun 2022Cites it
Hot water heaters frequently have sacrificial anode rods to prevent corrosion. The rods corrode over time and dissolve into the water. Lower cost aluminum rods have health concerns, not as much with magnesium rods. See also Tom Scott's video on Britain's history with separate hot and cold taps and why hot taps sometimes had unsanitary cold water tanks to supply them: ▶ this video
in “Controversy continues over whether hot water freezes faster than cold” · View on HN
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stevekempNov 2021Cites it
On the topic of mixer-taps in bathrooms, the UK typically has separate taps due to the way the water is stored, or used to be stored: ▶ this video I was pleased when I remodelled my bathroom there and installed a mixer. So much more convenient.
in “Culture shock” · View on HN
msieAug 2021Cites it
At least in Britain, if there are separate taps for hot and cold, you shouldn't trust drinking from the hot tap: ▶ this video
in “Bottled water is 3,500 times worse for the environment than tap water” · View on HN