Having just removed mine this week, I'm certain it is hooked up so that the flow is from the water pump to the control valve, then into the core. As explained elsewhere, I think by Red58, you want the valve on the supply side. This keeps the core from always being "full on" with pressure. My apologies to the original poster if I got it wrong.
I admit not yet fully understanding the function of the capillary tube except that it is some type of crude "climate control." New valves sold at parts houses do not have this feature. (Draw your own conclusions.) However, being isolated from the hot supply would only increase flow.
I'll keep watching the thread. I'm learning from reading.
Bill
