hydronic heater is on in summer

My A/C has not been working well. I went to the attic to check it and found the hydronic coil warm (estimated around 110 oF). From the water heater, I closed both the inlet and outlet valves from and to the hydronic unit on the attic.
I know almost nothing about hydronic heater. My question is: is it safe to close the valves? Would closing the valves hurt anything?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Is the pump running, is it still heating, turn it All Off.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.