shower valve weirdness
 

i have a feeling i know the answer to this, but i need some reassurance before i start tiling with no turning back.

anyway, i have the shower valve installed with the plug and bonnet, pending tiling, and then the cartridge will go in.

i tapped into the hot and cold water lines underneath the kitchen sink, came right through the wall, and then T'd off to lav and shower and toilet. i installed a shutoff valve at the beginning of each line.

anyway, turning on the kitchen sink results in both faucets delivering hot water.
and i had weirdness the other day testing the valves in the bathroom, hot coming out of cold, and vice versa, depending on which was opened first.
obviously the lines are both being mixed inside the valve and just going wherever they want, right?

so when i install the cartridge all this weirdness will go away?
i'm just wondering, when someone is taking a hot shower, what keeps that hot water from coming out of the cold tap in the kitchen sink?
thanks.

Yep--That's it.


Sure would have been a nice if they put a sticker on the valve plug.

Nothing. First come first serve is the anomaly in this case. I'm thinking this will also be grounds for a divorce. Showers should be supplied from the source and not tapped off of nearby plumbing. And even then.......!:)