Trouble getting air out of system

JK_2

Any help would be greatly appreciated. Also, I wish I had more information but I'll type all the information I have on this system. It is a three zone three floor house. It is all baseboard radiators except for the kitchen which is a wall mounted radiator. There are two zone valve the kitchen radiator has a thermostatic valve and there is one circulator on the return. There also has been two addition on the house over the years but no new boiler. All the baseboard radiators do not have bleeders on them, but the kitchen one does. The supply pipe is 1 1/4 copper and all the baseboard are supplied with 3/4 copper. The kitchen radiator is supplied with 1/2 pex tubing. There are 5 loops all have purging valves except for the one loop which does part of the second floor. After I made the repair to the leaking basebord on the 2nd floor I then tried to purge the system. First, I isolated each loop except for the one on the 2nd floor. I then put the hose in a bucket opened the fast fill on the fill valve and waited for all the bubbles to stop flowing out of the hose and moved on to the next loop. After, I was done purging the system and I thought I got all the air out I set the pressure in the system to 18 psi (it has compression stlye x-pansion tank). I fired the system up and I could hear the air in system gurgling and circulating around. On all the return loops I as getting hot water back and I checked each indivual radiator to make sure they were getting hot and they were all of them. This boiler is in a tight location plus it is next to a water heater. So, there is no room to put in a spirovent or an air scoop because I think you need 18 inch from any elbow and there is not enough room? The customer was very nice and told me that it has been like that for years and years and that is all I could do and it is fine with her. I wish there was something I could do to get the remaining air out. The pressure in the system stayed about 20 psi with the system running and at the water limit of 180 degrees. Is there anything I can do to get the air out? Is that one loop without the purging valve causing the problem? Thank you in advance for any help.

Canuck

Time to relax

You say that you're getting hot returns on all of the loops. That's great! That means that the air entrapment is not so bad as to air lock one of the loops. Given some time, (I'd say less than a week), the rest of the air will have gone into solution, in the system, and the noise will disappear. Betcha CDN $5.00 (that's about US 50 cents)