A Hissing Radiator and Sleepless Nights

The first question should be what kind of steam fed radiator is it? Single line or return line? Most of the comments here seem to be addressing single line systems, where the hot steam comes up via a riser, then stops when the building thermostat or timer indicates the building has complied with heat delivery, and returns the steam, condensed, back to the boiler, via the same line. "Knocking" or loud concussive sounds can occur when descending condensed water encounters rising steam in single return lines. Double return line systems send hot steam up via a feed and return condensate via the 'return line' to the basement. They use more pipe so they're less common and far quieter, but, can have problems too if improperly blocked or poorly maintained. In single line systems the radiator should be pitched to drip back into the 'feed' valve side. In return line systems it should be pitched to drain in the direction the return line exits. Release valves help prevent surges in pressure from blowing up your radiator. They aren't supposed to drip and ruin your floor and your downstairs neighbor's ceiling. People warning that you should be sure the heat is off before removing the valves are correct. You also don't want the valves being poorly attached with inadequate 'packing' and getting blown off, with hot steam filling your apartment and causing all sorts of damage. If you find any of the above intimidating, bribe or tip your super to take care of your valves.

I'm struggling with the same problem right now. This is NOT a plumbing problem, this is a HVAC issue. The landlord needs to pay a specialist to evaluate the entire building. First, is your radiator raised? Under the vent, there should be a 1-inch piece of wood tilting it towards the knob. Second, go for the brand Horton for vents. Third, there are a variety of vent sizes, so pending if your apartment is too hot/cold dictates the size of the vent. Finally, if the landlord doesn't comply, you might want to work w/your neighbors to get the whole building balanced. Someone else's radiator could be causing your issues if the above doesn't work. Good luck!!

Whenever the air valve is removed from the radiator, there is danger of escaping steam and burns. Be certain to turn off the steam supply or shutoff valve that is frequently located near the floor. This often has a large plastic knob.

if you wrap the valve in a towel and tie it, it will be a temporary fix. I did that in my apartment for years.

It’s good advice to change the air valve. As someone here noted, once it heats up it should close down, and no air should escape, preventing hissing. It’s a very simple thing to do, and your super or a handyman can do it. They need to wrap the threads with Teflon tape in the proper direction so that it doesn’t get disturbed while screwing it into the hole in the radiator. It also needs to be done while the radiator is cold, not when heat is coming up to avoid being scalded by steam. I wouldn’t quibble over who pays for this; you want to sleep better, just do it. The advice from the lawyer who says that a hissing radiator violates the warrantee of habitability is ridiculous, and an overreach. Not having heat would violate the warrantee of habitability. Complain to a judge in housing court about a hissing radiator, and you’re likely to get laughed at and advised that you are lucky you have heat.

Radiators? What are they? I recall an Hungarian woman telling me she was never so cold in her life until she moved to Australia. Why? Because central heating is almost unknown here.

I've lived in a Hell's Kitchen rent stabilized apartment with 4 radiator and steam pipe valves for almost 30 years and have always changed them myself when they get noisy. It takes 5 minutes. Here's a YouTube video showing you how: https://youtu.be/y0VQOZqiw7U.

As an interim solution, how about just turning off the radiator completely and using an oil-filled electric radiator while you sleep?

The letter writer asks, "Is there is a way to fix this?" The plumber says, "There are no solutions." But if the letter writer were a homeowner and the plumber said that, would she believe him? Of course not, there must be a way to fix this. The radiator is making an incredibly loud noise.

Hardly anyone understands steam heating nowadays. It's a fine technology when it's working well. If there's a lot of "clanging," that's caused by an improper arrangement of piping in the boiler room, and it may take a lot of work to fix it. But a hissing vent should be simple. David of Flushing obviously knows a good deal. If your valve hisses loudly, it probably doesn't close, and it's letting steam out Replace it. If it's a "silver bullet," maybe another of those will do, but for a few more dollars you can buy a Gorton valve, which is of higher quality. If you're interested in exploring the subject, the book is "The Lost Art of steam Heating" by Dan Holohan. BTW, Ms. Pillon's drawing shows a vent at the bottom of a radiator; it would really be at least halfway up at the end opposite that of the valve.

I should add that my father-in-law, who had kept the old radiator valves, put them back on when we left.

When we lived in a rental apartment, we fixed things. Why not? The linoleum in our pre-war kitchen was ragged, so we ripped it up and put down linoleum squares. Nice job. The black linoleum in the hallway and foyer was coming off on our bare feet -- I think it must have been put on by the first tenant -- pretty awful. We pulled it up to find exquisite parquet, on which we had to use boiling water and Mex in order to get up all the old glue, and then we shellacked it. Some mold spots on the bathroom ceiling? Wash it with diluted bleach and paint it with anti-mildew paint. We were there for over twenty years. Our building manager, pleasant and reliable, took care of plumbing, heating, and paint jobs. Radiator valves? My father-in-law had some better ones than what was there (or what, probably, the manager would give us), installed them, and removed them when we bought a house. All of which is to say: Tenants are not helpless. Just because we pay rent doesn't mean that we can't make our living conditions nicer. It might be a rental apartment, but it's your apartment. Buy a valve. Get a plumber to put it on if you're unsure whether you can or not. But it's really an easy task. Don't forget to use silicon tape.

If the air valve continues to hiss once the radiator is hot, it is defective and needs to be replaced. Only room temperature air should come out of it. There are a number of air valve designs and not all are of the "silver bullet" form. Often there is a number on the valve which is the manufacturer's size designation. The larger the vent hole, the faster air escapes from the steam pipe. In theory, the steam system should be "balanced". Often this means having smaller holed valves near the boiler and larger ones in more distant places. When done properly, steam reaches all the radiators at the same time. In practice, people turn off radiators in overheated apartments so that more air has to escape from those radiators that are still turned on. The main downfall of air valves is particles of rust that lodge in the narrow exhaust channel. These can prevent steam from entering a radiator (steam is denser than air) or prevent the valve from closing causing constant hissing. The rust can even form an efficient whistle. As mentioned, air valves are cheap and easily changed by the super---no plumber is required.

If the super seems competent, also get him//her to buy the replacement valve and reimburse the cost. Otherwise call Mr. Krause, the pumber mentioned in this article, and hire him or one of his people to do the work. If you can afford a renovated multiroom apartment in Hell's Kitchen your time is worth money. The landlord has alreay proved that s/he will send someone not so competent. I know in a scrupulously fair world the cost should be the landlord's; sometimes life is not quite fair.