I have a strange problem with my hot water in a house that is new to me (constructed in 1997). When I turn on the hot water in my bathroom sink, it gets very hot. When I turn on the hot water in my shower it only gets warm. When I turn on the sink and the shower, the sink is cold, and the shower is hot.
I've noticed this behavior in other parts of the house too.
I think there is a recirculation pump on the system that is currently unplugged from the electric outlet.
Any ideas?