-
Already installed a new auto fill valve.
-
valve off make up and bypass and see if you still have problem. B&G says to close outlet of prv when system is filled. could it also be just a leaking relief? not much else going to cause this problem besides what has already been stated.
-
Two weeks later and this problem still exists? I'm surprised you, or your boss, haven't already called in someone who is experienced with this type of system. The systems like this that I have seen either are in the cooling mode (water flow directed to cooling tower for heat rejection), or in the heating mode (water flow directed to the boilers for a heat source). Not both at the same time. The fact that you are seeing the same pressure (45 psig) at the cooling tower and the boilers at the same time indicate that either flow is directed to both, or neither. The fact that both those pressures are equal to pump discharge pressure indicate that there is no flow at all. Pressure should decrease, overall, as distance from pump increases. With allowances for variations due to height. You should be using one gauge, moved from tap to tap, to eliminate gauge error. If you have verifiable good gauges, then you can probably rely on multiple gauges to check for presence of pressure changes. But I would not rely on seperate gauges to tell me how much that change, or difference, is. Strictly one guage for that. For what it's worth, I suspect that while draining and refilling the system, a valve or two was overlooked and is in the wrong position. Maybe it's linkage (including internal) broke and it is not in the position you think it is. A shut valve, or any type of flow restriction, will have a significant pressure drop across it.
