My radiators had popping and little clanking sounds, minimal bubbly swishing. Kept having nightmares the pipes were bursting... Our utica boilers are from 1983. Saw that the pressure was in the 30's and drained some water hoping to reduce pressure. (we are new homeowners, 2 flat, 2 boilers, learning as we go). One boiler's pressure stayed at 0, while the other was rising into the 60's and we panicked and called a 24 hr heating cooling company on a Sunday and paid $85 for the 30 minute visit.
The guy explained :
our pressure relief valves (don't know the difference between that and a pressure reducing valve after reading this thread..) are the wrong kind (allow for 150 psi vs. 30).
Expansion tanks are too small ( we need a 30), need replacing
One of the feeders(?) had a blockage or was broken, need replacing.
We manually fed water into that one (he wouldn't do it, but allowed us to).
It looked like replacing the parts could be something we could dowith my handy dad, but dad felt uncomfortable doing this in case something went wrong. He referred us to a different guy he used.
Long story short, they replaced:
unit 1: expansion tank, pressure relief valve, air vent, feeder
unit 2: expansion tank, pressure relief valve, air vent
My dad gave him our check and I called the worker as I was not home. He said everything is good except that the feeder valve on unit 2 needs replacing as well as the water keeps leaking into the boiler a little but he didn't have the part then. He told me to turn off the lever (was on for 4 hours at that point). I asked if they relieved air from the radiators in the units and said there was no need, they did it all in the basement (initially they told me they needed access to the units so I arranged for it).
I came home and it sounded like little waterfalls in surround sound all over my apartment. It was very loud. I called and he blamed it on air getting into the system again because of the leaky feeder, and offered to replace it in the morning. I said we'd have to sleep elsewhere for the night as it's REALLY loud and I worried the pipes may get damaged. I was assured the pipes would not be damaged and after some convincing he sent a guy out to get the air out (in the basement boiler room). It did not help. He said they need 2 people for one to bleed the radiators while the other is bleeding the air in the boiler room. I offered to bleed them upstairs but he wasn't responsive. we are up ALL NIGHT.
I plan to be very polite and to trust them, I just want to be educated.
After they drained the system and refilled it, can there be anything else wrong in the system that could be causing this trouble? Could they have incorrectly fed the water back into the system (they did drain all of it)? THe pressure is at 24, winter in Chicago. Is this ok or should be be under 20? Could this swishing around be doing any damage (I worry about sediment getting dislodged and causing a blockage, pipes getting distressed, etc...) Anything I should be on the lookout for?
The airvents look small and different and I want to know that they are working. How do I know if they are the correct ones? Do they come in different sizes/quality? The guy who came later said that the air vent can't handle all the air that's in the system now, but I think I may have heard a quick hiss only once while listening for it. I have no research to back up my suspicion of the air vents,, just an intuition/paranoia.
Any insight, expertise, or experience, would be GREATLY appreciated