Hot water only working sometime in upstairs faucet (heater, bathroom, kitchen)

[rlmcgrath1]

Our hot water works in the kitchen faucet after I go into the bathroom (adjacent to kitchen) and turn on the hot water at the same time I have the kitchen water running. It then gets hot and works until I shut it off again.

Any other suggestions on what could be causing this?

[Narfcake]

Do you have a tankless water heater? Too low a flow means it won't kick on, hence no hot water when only one faucet is opened.

[Charles]

Originally Posted by rlmcgrath1

Our hot water works in the kitchen faucet after I go into the bathroom (adjacent to kitchen) and turn on the hot water at the same time I have the kitchen water running. [Does it work if you don't go into the bathroom and run the water???] It then gets hot and works until I shut it off again. [Does it stop working unexplainably?]

Any other suggestions on what could be causing this?

What is the problem? You wrote that it works when A, B, and C occur. You didn't write anything about it not working under any circumstances. You didn't write anything about it work "only if" some other condition was met.

[KonaKat]

Could be your mixer valve in the faucet is not working right. They get corroded and "freeze up" sometimes.