I would like to see a picture before I comment.
800 pixels or less would be nice.
I have a 20 story hotel that we were called too. They have centeral boilers in the sub basement on the 6th and 12th floors that have 1.25" copper lines that they claim are the recirculation lines. The piping is a mess and its hard to tell where anything is going. Their are (2) recirc lines with 1/2 hp recirc pumps that to me look like they are going into a heat exchanger. Im not sure if its even a heat exchanger. Its about 6" round and 30" long in a tube shape. It has a t&p on it and the other end is flanged. Both recirc line pumps are pumping into this device and 2 lines are leaving. The device, what i think may be a heat exchanger has what looks like a small sample port on it and also a 1/2" threaded nipple and valve stubbed out the side. I was thinking that maybe this was a steam line at some point, its not hooked up to anything and is puzzleing me. At the oppsite end of the building it is taking to long to get hot water to the fixtures. I will get a picture of this, its very hard to explain. This is in the domestic hot water line? I know its a long shot without a picture, but the device is so old i can not read anything on it. Any ideas?
That large of a recirculation line could have multiple connections into it, and if so they could be unbalanced so the furthest ones do NOT circulate. There could be other possibilities also, such a having Mixet shower/tub valves which are notorious for causing this problem.
Licensed residential and commercial plumber