h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I live in an old rooming house constructed circa 1927, approximately 90 rooms, single pipe steam. The building super says the boiler (new two years ago) runs at 5 to 7 pounds system wide. He may or may not know his brass from his woodwind.

My radiator worked fine last year. Valve was shut off near the end of last winter, and has been off all summer. This year, at the beginning of the heating season, my radiator was full of water. Now, whenever the boiler cycles on, water comes out the vent. The radiator continuously refills with water, never steam. In the last 24 hours I've drained over fifty gallons off, instructed to do so per the building super. Somewhat more than 300 gallons in the last week. I also tilted radiator 3/4 inch, as per super's instructions.

I don't see the problem being a faulty valve because the same problem exists in a series of adjacent rooms -- all those on my short hallway. Can anyone advise?

John Sinclair, Salt Lake City

*Steam* heat is not supposed to do that!

First let's make sure we are talking about the same thing. In this picture the air vent is the one in the upper right, although it might not always be at the top of the radiator it will probably be at least halfway up or higher:
http://www.mtholyoke.edu/proj/cel/cep/anjanette/Images/heat%20brochure%20Rocky%20North.jpg (and the picture labels it a "valve" but "vent" is a better word).

And you are saying that the water is coming out of the *air vent*? That should never happen. It could indicate that there is a blockage in the pipe somewhere so that the condensation cannot drain (assuming you are on a lower floor, and there are radiators above you that drain down past yours). Or, theoretically at least, the pressure is too high and is driving water up the pipes - like a pot boiling over - and the heat should be turned down at the boiler. For a single-family home, pressure is only 1.5 to 2 pounds, but I have no idea what it should be a for a large building like yours.

And you do have the steam valve (lower left in the picture) fully open, correct? There is no halfway with that, it either has to be open all the way (so the water can get out) or closed completely (so the steam can't get in). If you have it partly closed, that's your blockage right there. Open it.

On the other hand, if the water is coming out of the steam valve, that's just a simple leak. It should be tightened, repaired, or replaced.

And then you might have hot water radiators, in which case they should fill with water and you're just wasting your time trying to drain it. Double-check that this really is a steam system.

I'm not an expert, but I've dealt with my radiator and I'll tell you what I've learned.

My heating season started October 1 (a month and a half ago) and I had my steam valve closed all the time (but I didn't know that it had to be shut TIGHT).

Everything thing was fine (no noise until last Friday night), but it started making a rattling/vibrating kind of noise because it filled with water to the level of the vent (bottle/canister shaped "Hoffman" vent).

The piece of the Hoffman vent that goes INSIDE the radiator is a "tongue shaped" piece of metal that will vibrate when the boiling action of accumulated water (condensate) shakes it rapidly (the tongue shaped piece of metal is a moveable piece of metal meant to act as a switch).

If you open your steam valve (after the boiler shuts down and the pipes cool), then the accumulated water will drain back down to the boiler (let the water drain for a couple of minutes).

If there is still steam in the pipes when you drain, the steam will "knock" against the water.

It's usually not popularly known, but the round handle on the steam valve is not enough leverage to properly close the valve, you have to use pliers to TIGHTEN the valve closed (or else it will keep accumulating water from the condensate, but won't let it drain).

The radiator is supposed to be on a floor that is LEVEL, but over the years, wooden floors sag. In that has also happened, you will have to slightly raise the end of your radiator that is opposite the pipe/steam valve so that the radiator can drain the water back down to the boiler. If the floor has sagged ALOT, then you should get your superintendent to raise the radiator (because if you get a leak in the pipe joint while raising the radiator, you don't want it to be your fault so that the downstairs neighbor complains to YOU.

I drained my water Friday night (apparently not ALL of it) and can hardly hear any noise at all.

In my search for info online, I found out that there are two types of radiators that can be distinguished by sight (make certain identification of yours)...

http://www.radicalradiator.com/index/pg29685