Losing Pressure HW - No leaks

Posted by KT on January 26, 2004 at 13:00:46:

I have a WM hot water baseboard system that has had what I believe to be leak under concrete slab. I have bypassed all underground piping and brought all connections above ground. When the system was not running, it held pressure fine. Now that it is colder, the system is running day and night and the pressure has dropped about 1-2 pounds in the past 3-5 weeks. I have tried purging per the instructions posted here and in the Hydronic BB. I do have air in the system, but I'm not sure if it's from a leak (would I see water?) or if I never got it all out from the original refill in the fall. I have an air scoop that I've closed the valve cap for a day or so, and loosened it to let a substantial amount of air out.

I have an old expansion tank that I cannot shut-off from they system.

Can I assume there is air in the tank that is causing air in the system, and ultimately escaping through the scoop and consequently lowering pressure?

Any other reason I still have air in the system? The system has been filled for 2 months and air has been escaping daily from the air scoop. Should'nt it be out by now?

The heat works fine. But the boiler does bubble and kettle.
Thanks!

Follow Ups:

• Harlold- Can't read response (?) KT 07:05:48 1/27/2004 (0)
• Re: Losing Pressure HW - No leaks KT 15:01:10 1/26/2004 (0)
• Re: Losing Pressure HW - No leaks Harold hydronicnetwork.net 13:30:18 1/26/2004 (0)

Post a Followup