This is a usability question regarding a class of one handle mixing faucets that I encounter frequently. My SO and me differ on what is self-evident what direction leads to hot/cold water output.
An example (for a basic kitchen sink faucet) is this (page from Amazon Germany).
There is a marking for the directions associated with warm/cold water: left semicircle red=hot, right semicircle blue=cold. A marking on this place (on the handle, i.e. the marking turns with the handle) seems to be pretty universal for mixing taps (both bathroom sink and kitchen sink type) that I have seen.
I’ll put my and my SO’s reasoning into a spoiler box - please read only after answering the poll.
My reasoning: self-evidently turning the handle to the right (as seen from the front) means hot water - because the marking turns with the handle, and turning the handle to the right turns the red=hot semicircle towards the operator, and the blue=cold semicircle away from him. (if the red/blue marking were not on the handle but on the fixed part this would not be so; in that case turning the handle to the right would mean cold water.)
My SO’s reasoning: self-evidently turning the handle to the right means cold water, because the blue=cold semicircle is on the right.
She is right, and I frequently scald my hands and even more sensitive parts mildly because I am overthinking this
Turn the handle to the right is cold. It’s not just the markings on the faucet, but every faucet I’ve used in every country I’ve been in since 1970 has had the cold on the right.
While I’m sure there are places where that’s not ubiquitous, I think it’s fair to say it’s most common.
My experience is the same, but we had a thread on that a while back, and while that definitely seems to be the vast majority, it’s not universal, apparently.
Anyway…both instinctive ‘right equals cold/left equals hot’ and the way that thing is marked point to ‘turn right for cold’ to me. Think of the semi-circles as arrows - the ‘hot’ one points left, and the ‘cold’ one points right.
You **are **over thinking this.
However, although I voted for the first option, in practice I always test the water first because there are a lot of DIY plumbers out there.
The circle doesn’t suggest anything about how to turn it. Actually, I’ve never seen a faucet like this that literally turns anyway - they’re basically a lever you tilt left or right.
This isn’t an answer to the OP’s question, but it’s a good way to eliminate all confusion :
Hot water is always on the left.
Why?—Because ,in the old days, there were two separate knobs on the faucet*, and you would naturally reach out with your right hand to turn the knob on the right side, and your left hand to turn the knob on the left.
Most people are right-handed, so their first instinct is to reach for the knob on the right. Especially children.
So, the knob on the right side is cold water, for safety reasons—to avoid the danger of scalding yourself from that first blast of water, which may be hotter than you expected.
*(that’s a “tap”, for those of you who spell color with a u)
As others said, I can’t recall ever seeing a faucet where it wasn’t left for hot, right for cold. Even putting that aside, I think the OP’s reasoning is overthinking it. If one side is marked blue, the first thought is that it is the cold side, not that if I turn it in the opposite direction more of that would be facing me. That is, it just strikes me as one extra step of complication.
That said, I have seen some faucets that are a bit ambiguous about which direction to turn. I seem to recall a shower that had a nob you would pull to turn on or push in to turn off. It was in the middle of a circle with the typical left side red and right side blue, but the actual handle part of the nob was on the bottom. The intention was that the top part of the nob would point into the color so, somewhat counter-intuitively, the handle would go left to make the top point right into cold and vice-versa for hot.
Even if you don’t understand the concept of a standard with cold to the right and hot to the left it is still clear that the symbol indicates cold on the right and hot on the left. The reason is that there’s no fixed indicator, the symbol moves with the handle. If there was an arrow on the faucet stem below the symbol, and the symbol was much wider so that the colors would align with the fixed indicator, then your method would make sense. That’s not the case, and I’ll suggest you let your wife make the common sense decisions for you. I’m sure she’ll agree with me.
It’s very hard to answer, at this point, what’s intuitive and what’s not about the labelling.
After having encountered these for years, like others I “just know” that left will be hot, right cold. I wouldn’t even bother checking the label. And this is just as well, because many, even most, of the taps of that sort I encounter either have the label rubbed off, or it was too small to be seen in the first place without bending right down and peering myopically at it.
We’re not steering using a boat rudder or flying an aircraft into the sky here, where directions are reversed. So the direction something is indicated, is the direction you go to get it.
Putting aside the fact that all faucets I have come in contact with thus far locate cold on the right and hot on the left.
My mom has an odd tub. To turn on the hot water, turn left faucet counter clockwise. To turn on the cold water, trun right faucet clockwise (which to me would be turning the cold water off).
Whoops – I voted wrong. I’m one of those people who periodically get their right and left mixed up. You know, the type who say “Turn right” and then, when you start to turn right, say, “No, no – turn right!”
Historically, counter-rotating faucets were quality ones. Installed properly, they should rotate outwards for on, e.g. Left/hot side rotates counterclockwise for on & vice versa on the right/cold side.
Having both H & C where e.g. counterclockwise was on and clockwise was off was low-rent cheapo stuff. It’s still that way today.
What always gives me pause is traveling to Spanish-speaking countries where the left knob is labeled “C” and the right is “F”. I know the relevant words and it works fine if I see the “F”=frio side first. But if I notice the “C”=Caliente side first my brain stutters for a moment or two. Even if I’m in country for a couple weeks straight it still triggers a “Huh, what?? … <gears grind> Oh yeah, duh.” reaction.
The only ones I have trouble with are the ones where the handle is just a round knob. Then it’s not even clear what “turn the handle to the right” means.
All of this would be crystal clear if they would use arrows instead of semicircles.
I know of a similar one, but it’s all one faucet, with two knobs that operated in the way you describe. I think it’s because it was a self-installation job done improperly. The place also had windows put in backwards and stuff like that, until this last year when the windows were replaced.