Radiator is loud, way too hot, and won't shut off.

Nick_39

Hi all. I'm hoping for some help diagnosing the problem I'm having with one of the radiators in my apartment. It's an old NYC building with steam heat and no individualized thermostats in the apartments. I'm on the 7th floor in the middle of the building. There are 5 apartments per floor. Not sure where the boiler is exactly. My living room has one radiator which has not been a problem. The bedroom has a second which has been a major problem.



When the building turned on the heat for the winter, I was quickly too hot in the bedroom. I shut the valve coming in to the radiator as tightly as I could. I'm relatively strong so I think it's fair to say it was closed pretty tight, though I'm sure with proper tools it could go tighter. I was still getting some heat from the radiator, but it was manageable. Then I started to get loud banging in the pipes. This primarily happened in the mornings, presumably when the thermostat was turned up. I've been enduring this for a while, but it's been getting worse and worse.



I know the banging is caused by water condensing in the pipes and not being drained away before it can accumulate. Unfortunately the radiator has a weird L-bend which prevents me from angling it to allow proper drainage. See the video I linked to below.



So yesterday I decided to see what happens if I open the valve. I was hoping (without much basis) that the banging would stop, and that I'd just endure it being hot in order to get quiet. Well as soon as I opened the valve I knew something was wrong. Within minutes the radiator was immensely hot, and the release valve was whistling like a tea pot just before boiling. It quickly got to be sweltering hot, but I decided to leave it for a while to see if relieving the pressure in the system would help. It kept going that way, so after a few hours I shut the valve as tightly as I could again.



I thought it was at least back to where I started. I went to bed last night expecting that I would probably get the banging again. Instead around 5:30 I woke up to the release spewing hot air like it had the previous day. I'm not that light a sleeper, so it was pretty darn loud. And it quickly started heating up the room again. Mind you, this was with the valve closed tight. So without a better idea, I tried to tighten the valve more. All I accomplished was to shatter the handle on the valve.



The radiator continued to heat up the room and make noise until around 7 am. Then it stopped for about 30 minutes, then it came back on for another 45 minutes. Then maybe 15 minutes of quiet before it came back. It was still on when I left the house this morning at 9 am. I opened the window and shut the door to the room because I didn't know what else to do.



I recorded a video on my cell phone to show what it looks and sounds like. The noise in the video sounds like it's static, but it's not. It's just from the radiator. Here's the link:

<a href="http://www.youtube.com/watch?v=sGGR6_1GBAw&feature=youtu.be">http://www.youtube.com/watch?v=sGGR6_1GBAw&feature=youtu.be</a>



The radiator in the other room appears to be a newer model. It has a straight pipe and has never made much noise.



So clearly something is broken. Maybe more than one thing. Does anyone have any thoughts on what needs doing? I described the problem to my super. He suggested getting a plumber to replace the shut off valve. Is that the best course? I'd really like to rip it out and put in a new radiator all together. But that probably has to wait till spring. I'm open to other suggestions though.



Thanks in advance for any help!

Mark N

Convevtor

Nick what you have is a convector on a one pipe steam system. In one-pipe steam the supply valve needs to be all the way open. The thing on the other end is the air vent. As the steam enters the convector the air is pushed out through the air vent. It seems that the steam pressure in your system is way to high. You should not hear the air venting. When the steam reaches the vent it should close. The vent on your convector way need to be replaced if it doesn't not close when the steam reaches it. The people that maintain the boiler need to get the pressure down as it just wastes fuel and causes all kinds of other problems, some of which you are now experiencing.

Jamie Hall

Mark's on it...

First, the valve needs to be open all the way.  Otherwise it will gurgle and bang and make a nuisance of itself.



Second, the way to shut one of those things off is to take the vent (on the other end) and turn it upside down.  Then it shouldn't let the air out, and if the air can't get out not much steam can get in.  However, it does sound as though the system pressure is much too high -- in which case that vent may well be broken.  You can get new vents in varying sizes (some are adjustable).



Third, see if you can get your super to check the system pressure.  Remind him that the Empire State Building runs on 2 psi and he doesn't need any more than that!

Nick2

Thanks.

This is the same person as the original post. I had trouble logging in and the button to send me a new password didn't work, so I just created a new account.



Thanks for the quick help. I'll ask my super about the psi and about replacing the vent. A couple follow up questions:



When you say turn the vent upside down to seal it, does that mean to unscrew it and reattach the other way? I can't imagine it would reattach upside down. But I also can't think of any other way to get it upside down...



If other apartments have their vents closed off, will that increase the pressure I'm getting? I'm on the top floor. If so, is there anything to do about that?



Thanks again!

Nick2

Also

if the pressure is the big issue, why would it not be an issue on the other radiator in the apartment?

Mark N

Vent

You can't turn your vent upside down as it is a straight shank vent. You can remove the vent and put in a pipe plug. Not sure what size you would need.

SchenleySeven

foil

Looks like a Hoffman 4a, which would have a 3/4" outer thread.



Temporarily, you could unscrew the Hoffman vent, put a few layers of aluminum foil over the base of it, and screw it back in.