Greetings,
I purchased a home with a boiler and hydronic baseboards. When I pressurized the system there was a rapidly dripping leak inside the boiler which dripped down onto the flame. I drained the system, removed the temperature/pressure relief valve, and poured Silver King (kind of like radiator stop leak) mixed in a bucket of hot water into the system. I ran the system with the temperature dial set at 160 deg F as per instructions for two hours and although the actual temperature fluctuated between 130 and 180 during this time the drip did stop. I then put the temperature/pressure relief valve back and pressurized the system. I opened all of bleeder valves that I could but several were corroded shut and nothing came out (even before the boiler stop-leak when I pressurized the system the first time). I then drained the system and replaced four or five bleeder valves and pressurized it again. I bled everything starting from the furthest away bleeder and moving towards the closest one. The "furthest away bleeder" isn't really the "furthest away one" because water flowed backwards (opposite the circulator flow direction) through the pipes to reach the bleeders. I know this because the first water which filled the pipes was cold. When I bled everything I could feel the pipes were hot for a good distance (15 ft?) on both sides of the boiler. After 15 min or so the water was still not circulating so I bled the system and removed the circulator pump (A 1/25 hoursepower Taco 007). There was some crap in the circulator pump (not stop leak) so I cleaned it all out and dry-tested the pump for about 10 seconds. It spun freely so I put it back and pressurized/bled the system. The hot water was still not circulating. I took the wire nuts off of the circulator pump and tested them with a volt meter and it was in fact receiving juice from the boiler control unit. There is a 1" copper pipe coming from the circulator pump which splits into two 3/4" loops (one for each floor). After the split there is a valve which controls the amount of flow in each loop. I cut out one of the flow control valves to see if it was clogged but it looked clean and fully open. I inspected the portion of the line that I could see for check valves which someone may have installed in the wrong direction but could not find any but much of the line is inside walls, etc.
What gives? William
PS: If no one reads any of this because it is two long my current plan of action is to install a brand new 007 circulator ($80+tax) even though the old one worked once removed and claened. If that didn't work my next step would be to cut the lines and force compressed air through the lines to see if there is a blockage. My next step would be to meticulously determine the amount of water the system should hold and compare that to the amount of water the system does hold to ensure that there is no air left once I am done bleeding.