Sunday, 28 September 2014


It used to be simple when we had a hot tap and a cold tap!

Nowadays there are mixer taps, and so you have to know which way is hot and which is cold. So they use red for hot and blue for cold. Some of my taps at home have no markings do you just have to guess.

The classic version is more like this :-

Now, to my mind, turning the tap so that the red dot is aligned with the water spout should be hot, and with the blue dot aligned with the water spout it should be cold. So this would be hot :-

I am wrong, of course, and what it means is turn tap towards the blue dot for cold (anti clockwise) and towards the red dot (clockwise) for hot. What is confusing is the dots are being moved so you are not really turning the tap towards the dot, you are turning the dots too. If the dots were on some part that did not move, that would work. If the dots were arrows, or even triangles indicating an arrow head, I would cope much better. But I am learning that this seems to be the convention... If only Steve Jobs had designed taps!

But when it comes to something like this, I hope you agree it is different :-

My shower at home is very similar to this with temperatures marked and a button next to 38 degrees which you have to press to get hotter. It has a mark on the base and you turn the knob to align the required temperature with the mark.

The one pictured, I assumed, was the same, but instead of specific temperatures above and below the 40 degrees marked, there are red and blue marks which I assumed meant hotter and colder.

So I assumed that if you you turn so the blue markings are aligned to the notch on the back, that should be colder. Similarly if you put the red markings next to the notch on the back, it would be hotter. This is obvious, surely.

But no! This is like the tap, though in reverse, in that turning anti clockwise gets hotter not colder. Even though the notch matters in that you align the "40" with it to get 40 degrees, the red and blue are not indicating where on the dial is hotter or colder, but a direction to turn the dial.

And just in case you think it was plumbed backwards, no, the button stops you turning it as shown above. I.e. you have to press in order to align the blue marks with the notch to get hot water.

They fix this with a sign saying "Please check the water temperature", which is clearly an admission of a non intuitive interface to a shower...

(this was the shower in the cabin on the cruise).


  1. Another example of direction confusion - we used to have a small music centre with a remote control - among its buttons were a pair marked thus: "< VOLUME >" - instead of thinking of them mathematically (less and greater) which is correct, my sister thought of them as "crescendo" and "diminuendo" - so much so she even confused my mother who used to always go the wrong way first.

  2. I have a long-standing hatred of non-mixer taps (two choices: far too hot or far too cold!) - though some controls, particularly shower ones, can be very irritating too. The worst and probably most common fault I see is trying to combine the two dimensions of control, the volume of water and its temperature, into a single scale: having finally purged my home of the last non-mixer tap, next I need to kill off the sole "off-cold-hot" one in the bathroom. (Did it really never occur to the perpetrators of that product that the user might not always want the tap on full blast?!)

  3. I detest mixer taps. I never know if I'm going to get cold water, hot water or some mix. The number of cold drinks I've ruined with slightly warm water.... Or burned my hands when I was expecting cold water and turned it the wrong way. The marking just don't help. I HATE them, they should be banned!

    1. Reminds me of

  4. I'm assuming you take these out of the album before showing friends and family, lol.

  5. At least the colours are standard. Many years ago, my mother went as part of a group of young ladies to Wales. The taps had no colour codes, and were merely stamped "P" and "O" - my mother was one of the few who knew which was which straight away.

  6. A friend of mine bought an ornate kitchen sink in France and imported it into the UK for installation in his new kitchen. The taps were not labelled H and C, but C and F (it being French). He left it with his plumber/kitchen fitter to install. When he returned home, they'd connected the C to Cold and presumably wondered what the F stood for, but connected it to Hot.

  7. Can you not still get taps that have a mixer spout, but two taps to control hot & cold? Incidentally, "Mixer" is a misnomer in the UK - they aren't allowed to mix the flows until they reach the spout, in case the hot can overpower the cold and flow into the "clean" pipes (hot water is not regarded as potable and putting it into the drinking water stream is illegal).
    Next time I replumb a bathroom I'm going to fit a thermostatic mixer that controls the flows before reaching the taps, so "Hot" tap is actually "handwashing temperature" rather than "take your skin off"!

  8. And then we wonder how come carers still scald frail/elderly/vulnerable people when bathing them....