Follow up to "possible blocked radiator" situation

hws

Some of you might remember my thread regarding a "possible blocked radiator" which seems to actually be a direct-return system with a balancing problem>

Well today I began the process of trying to remedy the problem. First thing I tried was, thinking that maybe I made a boo-boo during the roughing in stage, cross the supply and return lines at point A in the attached diagram. Re-filled the system, purged air, and started it up again, and within minutes the whole zone, including the problem radiator, was heating. With the supply and return to the sub-zone crossed, every rad in the zone received heat. So far, so good.

I then took readings with the infared laser thermometer to see how out-of balance everything was. The two top left rads were the hottest at 130 degrees, the problem one was around 105.

I think with valves installed to throttle flow to the two top left rads, I can send some more heat to the sub-zone and hopefully even things out.