Advice on steam radiator air vent leaking water

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by patricke, Jan 27, 2014.

  1. patricke

    patricke New Member

    Messages:
    2
    Location:
    Massachusetts
    We live in a 130+ year-old house with steam heat, and have a frustrating problem with an air vent leaking water. Before I spend any more money on plumbing service calls, I wanted to see if the experts had any advice for me! It's a bit of a long story, but I'll try to keep it brief. Starting a few months ago, we noticed water stains in our living room ceiling. After opening up the ceiling, we tracked it to a bathroom radiator on the 2nd floor. We also noticed 2 other radiators leaking water at the same time. Our plumber replaced the air vents on all 3 radiators with new adjustable vents, and two of the radiators appear to be fixed. However, the 3rd one is still leaking - pictures are below. All radiators are single-pipe.

    20140125_121046.jpg 20140125_121116.jpg

    We believe this radiator may have been leaking for some time but we didn't notice since it was under a cover. Since we added the new vent, it's leaking less but still about 1/8 cup per heating cycle. It leaks out the top of the vent while under pressure and then has also dripped from the bottom of the vent once the cycle is done.

    Some things we have done already / additional questions:

    - Serviced the boiler. We recently had a leak in our service line at the street and the water company dug it up and fixed it. While doing so, they sent quite a bit of sediment into the house, so we wanted to have the boiler cleaned.

    - Set the vent to a low value, it's around 3 right now. When we set it to 7 or 8, more water comes out along with air.

    - The slope on the radiator is wrong - it slopes slightly toward the vent instead of the inlet. It's been like that for 100 years, so I'm curious if we should shim it?

    - I don't think the inlet pipe is blocked since we recently put a new valve on that since the old one was toast. So condensate should be able to run back down the pipe.

    - I read somewhere that the boiler pressure could be set too high? One forum said the lower the better, 1-2 PSI?

    - It is strange that several radiators would start leaking at the same time, all on the 2nd floor. What could cause that?

    Any help is appreciated! We're hoping to patch up the living room ceiling this week, once we can resolve the water issue. Thanks!
    Last edited: Jan 27, 2014
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,019
    Location:
    Cave Creek, Arizona
    Steam systems do NOT leak water, unless it is being trapped in the radiators, which could happen for many reasons, one of them being the valves are not fully opened.
  3. patricke

    patricke New Member

    Messages:
    2
    Location:
    Massachusetts
    Thanks for the response. The value is fully opened - could there be water trapped previously in there? Not sure if a steam boiler can send water up the line for some reason? Can we flush / drain the radiator somehow?
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,019
    Location:
    Cave Creek, Arizona
    If a one pipe steam system is installed properly ALL condensate water drains back to the boiler, it does NOT go into the radiators.
Similar Threads: Advice steam
Forum Title Date
Plumbing Forum, Professional & DIY Advice Steam Generator plumbing advice Jun 19, 2013
Plumbing Forum, Professional & DIY Advice Basement Rough-In - Need advice! Wednesday at 6:46 AM
Plumbing Forum, Professional & DIY Advice Intermittent well pump issues - advice? Nov 6, 2014
Plumbing Forum, Professional & DIY Advice need advice on 1950s Kohler shower faucet leak Nov 5, 2014
Plumbing Forum, Professional & DIY Advice advice on how to remove old faucet stem Nov 1, 2014

Share This Page