water turns cold after 5 minutes then hot again later
(los angeles, ca)
In one shower, the hot water lasts about 5 minutes and then turns cold. If I turn off the shower or just wait with the cold water running, about 5 minutes later it is hot again. But here are the strange things I noticed. When the shower is running cold, the sinks upstairs are still running hot. Also, if I run both showers at the same time, then the problem shower does not have the problem of getting cold. And another thing is that this does not happen in this shower all the time, its intermittent. I'm very confused and appreciate any suggestions. Thanks!