Thanks for the response.
To find the valve do I take off the handle and the plate behind it?
Is the probable fix going to be something a relatively handy(although by no means a plumber) guy can manage?
I had a Grundfos recirculation pump installed in my house a while back. It didn't seem to help a whole lot, but some. There is a shower past the sink where the valve was installed that we haven't used for a long time. We now want to use the shower again, and there is no hot water. Is it...