[bobvetter]

Five years ago I started to get a gurgling in the second floor pipes when the heat went on. I tried bleeding the pipes but in a few days the gurgling came back. Someone said I might have a leak so I shut off all the water except the boiler fill and after 8 hours the water meter did not move.

But out of desperation I added a leak stop liquid to the boiler and it cured the problem for 5 years. Now the problem is back.

My question is: if there is a contant 15 psi of water pressure created by the fill valve how does air get into the pipes? And how can I find such a small leak?

Bobv:

[ballengerb1]

Some of that air is in the water, H 2 O. Heating and cooling of the water can release some oxegen that is normally in solution. Do you have stand up radiators ro baseboard ? The bleed instructions will vary. By the way, the valve does not creat the pressure, it holds it.

[bobvetter]

Some of that air is in the water, H 2 O. Heating and cooling of the water can release some oxegen that is normally in solution. Do you have stand up radiators ro baseboard ? The bleed instructions will vary. By the way, the valve does not creat the pressure, it holds it.

But I did bleed the base boards and the noise went away for a couple of days but then came back. My system is two zone with the boiler in the basement and I don't have bleeders on the baseboards.

[NorthernHeat]

What does the pressure on the boiler read? Hot water or steam? I'm guessing by your post it is not steam but you never know if you don't ask.