Riser gurgling.

Shalom

We have here a 2 family house with 2 separate heating systems, one for each apartment. In 2008 we replaced the boiler for the second floor. (I was on vacation, boiler ran dry, low water shutoff didn't, and the tenant went down and added water to the hot boiler. So much for that.) It still shuts off on low water occasionally; I've had the system checked for leaks several times, including bashing a hole in my bedroom ceiling where there was a water stain to get access to the bottom of one of the upstairs radiators. (There wasn't a leak there.)



One of the risers to the second floor gurgles like all get out. I don't recall if it did this on the old boiler too. It sounds like there's so much steam going up, that it's not letting the condensate water come down. I tell you it sounds like half the water that should be in the boiler is in that pipe instead; so much so that I wonder if that's why it shuts off. (There's no automatic feeder, so I have to let more water in manually.)



The riser comes off the main steam pipe at the usual 45⁰ angle, then runs to the vertical at a much slighter angle, but not flat.



It so happens that a previous owner of the house replaced the radiator served by that riser with a gigantic unit that looks like it belongs in a banquet hall. It's about four feet high, maybe five feet long, and has five rows of thin tubing. I have no idea when or why this was done. We found the old radiator in the basement covered in plastic; it's still there now, in case it needs to be changed back.



So the question is, what of these factors, or any others I haven't mentioned, cause the gurgling noise? And is there anything I can do about it? Does a pipe need to be cleaned, does that huge radiator need to be replaced, or what? And if this isn't where the water's going when it shuts off, and there aren't any obvious leaks, where IS it going?

crash2009

open house surgury

Is this a 1-pipe or 2-pipe steam system?  I don't have much experience with 2-pipe so I will assume its a 1-pipe system.  Gurgling usually means that condensate is trapped by water or something else.  The first thing you can check is to make sure the radiator valve is all the way open.  Next go get a level and make sure the radiator is sloped (slightly) towards the valve.  Usually its one of these 2 things. 

If its a 2-pipe system the trap may need to be serviced.

The 3rd idea you are not going to like.  It involves "open house surgury"  It is possible that over the years the pipe to the problem radiator has gone bad.  If you jack up the radiator to level the pipe under the floor, it might just break the pipe and spill all that dirty condensate into the room below.  If this hidden pipe is leaking or has gone bad this could be the cause of your low water condition downstairs.  Steam leaks mostly evaporate, they dont leave a lot of evidence, like a water leak. 



Lets just hope the solution is in the first paragraph.

crash2009

open house surgury

Is this a 1-pipe or 2-pipe steam system?  I don't have much experience with 2-pipe so I will assume its a 1-pipe system.  Gurgling usually means that condensate is trapped by water or something else.  The first thing you can check is to make sure the radiator valve is all the way open.  Next go get a level and make sure the radiator is sloped (slightly) towards the valve.  Usually its one of these 2 things. 

If its a 2-pipe system the trap may need to be serviced.

The 3rd idea you are not going to like.  It involves "open house surgury"  It is possible that over the years the pipe to the problem radiator has gone bad.  If you jack up the radiator to level the pipe under the floor, it might just break the pipe and spill all that dirty condensate into the room below.  If this hidden pipe is leaking or has gone bad this could be the cause of your low water condition downstairs.  Steam leaks mostly evaporate, they dont leave a lot of evidence, like a water leak. 



Lets just hope the solution is in the first paragraph.

Shalom

I should have specified

It's a single pipe system. I'm pretty sure the radiator is properly pitched, as all that was supposed to have been checked when the new boiler was installed; they went around the house checking levels and replacing air valves. I'll have to ask the tenant whether the valve is open all the way or not.



If that pipe is stuffed up, I'm not looking forward to it... I suppose they could open it up and snake it out, but they're just as likely to come through the side of the pipe with the snake after 90 years of corrosion.

The Steam Whisperer (Formerly Boilerpro)

Gurgling

It is very likely that the radiator is making too much condensate for the pipe to handle. The piping and valves are sized to the radiator they handle.  If you put in a larger radiator in place of a small one the steam is rushing in at higher speeds through teh smaller pipe and won't let the condesate back down.