Why does it take so long long for the water to get hot in a kitchen sink? Water starts at heater and then at 8' feeds shower gets hot quickly, then at about 8' later feeds bathroom sink and gets hot quickly. At about 8' more is the kitchen sink and it takes at least 3 minutes to get warm. Recap appx 25' of 3/4" pex with 1/2" runs to the faucets, yet the first 2 get hot quickly and the last takes a long time, any ideas? The 1/2" runs are only about 5' each.

Rob

My faucets seem that way too - exponential cooling.
I suspect various factors: one is that the water to the kitchen has to flow past the bathroom feeds full of cool water and it mingles with some of that water, drawing a little of it along with it. And it's cooling off a little just because of distance. And maybe your bathroom runs aren't as near to an outside wall as the kitchen faucet is, further cooling the water. All that adds to need for more volume.
(And is it possible that the spacing isn't really 8' each? That the shower and basins are closer together, and the kitchen farther away?)

In my kitchen I keep a gallon jug for the first water out of the faucet, to water plants.
You can buy little under-sink electric water heaters.

Hi Rob

Shut the cold water shutoff under the kitchen sink and then see how fast the hot water gets to the kitchen faucet in comparison to the other faucets you mentioned. If there is a marked improvement in time for hot water to get to the kitchen faucet then it is possible that there is a problem with the mixing cartridge of the kitchen faucet (i.e., replace the cartridge and the problem should go away!).

Back to you...

Mark