Hot water works in the kitchen, but not in either bathroom (sinks or showers). Gas water heater is working. Plumber was out today to replace pressure regulator that had gone bad. Why would hot water work in one place but nowhere else?

It is possible there is a valve that is shut off if u have no water at all in some faucets.

Did this problem start after plumber did his job? He may have shut of valve and not turn it back on.

Chuck

The problem started before the plumber was here. I have cold water, but no hot. Cold water comes out when the tap is turned fully to hot. All faucets are one-handled.