My kitchen sink has an ordinary tap/faucet set: a hot handle, a cold handle and the normal pipe thing where combined hot and cold water comes out. So if both the hot and cold taps were turned on, one would expect evenly warm water to issue.
However, this faucet has a peculiar quirk. Instead of issuing warm water, part of the (single) stream of water is boiling hot and part is cold. If I were to tentatively poke one finger (or a similarly-shaped apendage) into the water stream, it would feel cold on one side of the water and burning hot on the other side. (Which is quite an unusual sensation–if you thrust your hand under the water, it is simultaneously scalded and cooled by the mixture of water temperatures.)
Any idea why this is happening? I would have thought that the hot and cold water would be thoroughly mixed as it gushed through the household pipes. How can sections of the same stream of water be at difference temperatures?
My sink does this as well. There is a fairly short (a few inches) run from the valves to the spigot (pipe thing). At low flow rates the two streams are fairly laminar and don’t mix. If the flows are turbulent, they will mix better. Try opening the taps until the flow is turbulent and check the results. You may also be able to put a little screen mixer thing on the end of the spigot to encourage mixing.
You have to remember that the hot and cold water stay in their own separate pipes while they are running through your house. They don’t come into contact with each other until they get into the actual faucet on your sink.
The best thing to use is an aerator. They screw on. Here’s a link showing their insides and installation. If your tap doesn’t have the suitable threading for an aerator, then hardware stores sell rubbery things that you can slide on over the tap. IMHO, those devices are incredibly tacky looking, unfortunately.
In the UK at least, this is because of building regulations. It is illegal to fix a tap where water direct from the mains supply (the cold) is mixed with water from a tank (hot). This is to avoid the mixing of the clean mains water with possibly contaminated tank water.
In the US RPBP’s (Reduced Pressure Backflow Preventers) are used in many applications to prevent water from the user’s side from backflowing into the supply mains. Hose bibbs or valves for connecting garden hose are a case in point. Toilet tanks are manufactured so as to provide a sufficient air gap between the supply and the bowl to avoid backflow.