water pouring from radiator vent

nysteam

I have 1-2 cups of water pouring from the air vent in my radiator. Seems much more than could be from condensate.

First floor of an NYC apt building, right over the the boiler room. ˜4 year old 1 pipe radiator, 84x19x5".

Water lukewarm.

The leak does not happen with every heating cycle, but when it happens, the tenants think it happens at the end of the heating cycle. This is confusing to me, but it's what they say. I was in the apartment a few days ago and observed the start of a heating cycle, a few drops came out of the vent at the beginning, but nothing after that.

It is sometimes, but not always accompanied by water hammer.

They report loud water hammer in the night and had taken to shutting the radiator so it wouldn't wake them. We asked them to leave the radiator open so water could freely drain. Since then, there is less water with each leak, but is still happens every couple days.

In the past month, the super has changed the valve twice. We increased the pitch of the radiator (˜1.5in over 7 foot) but leak still happens.

This is a new problem. Last winter, the same tenants were there, turning the radiator off to deal with water hammer, but there was no leaking. However, over the summer the building installed a new computer to control the operation of the boilers - so the cycling is different and maybe this contributes to the new issue somehow.

Seems like it must be the boiler throwing water - any insight about potential causes much appreciated.

ethicalpaul

Oils or other contaminants in the boiler water are the likely cause of what sounds like it could be surging. Was the water brown, or clear? Condensate is clear. Water from the boiler is typically brown.

nysteam

This was totally clear and not hot. Super says no other apartments in the building are having the same issue…

ethicalpaul

Then I would suspect some kind of pitch problem with the radiator or its supply piping.