Plumbing Work on Boiler Causes Problem with Radiators on Higher Floors

Maybe your radiators were always faulty and the steam boiler just wasn't producing much steam until they fixed it.

The radiator was new and worked perfectly before the plumbers worked on the boiler last work.

I've never had a steam system but the plumbing I think would be similar to hot water radiation.

It makes sense that a steam system would tend to have condensation in pipes or parts that have been left to cool after steam has been through. There should be a valve where such condensation can be drained out of your radiator - look for that at the bottom. But you can't drain it until the shutoff valve has been fixed, and you let it cool down first.

If the valve is stiff, maybe it just needs to be oiled/lubricated.

If you don't have a tool kit for this, call your landlord and tell him you need maintenance done to fix your radiator.

One pipe system.

If you and other residents had needed to shut off your radiators during the boiler work your landlord should have told you to do so or sent around someone who'd do it for you. Of course, your landlord might not have known that such action was recommended, and that omission might have nothing to do with your current problem.

Like others have done I'd suggest contacting your landlord. You really don't want the boiler blowing up.

Get the building landlord to bring the plumbers back in, threatening to withhold the rent until it is fixed.

Works a treat.

Depending on local/state landlord/tenant law, that might not be permitted.

You're right. In New York State other steps have to be taken before rent can legally be withheld.

The landlord or property manager needs to know about your problem. A sensible manager would want to correct the problem asap, to prevent any damage from being caused.

CR4 isn't about finding ways of not doing anything.

Being able to bluff is an important skill to be mastered.

If you can't close the valve completely, then either there is some kind of obstruction or the valve seal has failed. My first guess would be that either a surge of pressure or a sudden drop in pressure moved something like a calcium deposit into a position that prevents the valve from closing completely.

In any case, that valve should be opened and inspected. This, of course, requires that the steam supply be shut off somewhere between the boiler and your radiator.

My guess is that a load of crap got carried through the system into your valve and it either is closing on debris, or the valve seat has been damaged and won't seal any longer. It needs to be cleaned out and the valve replaced or the valve seat repaired. You could start by fully opening the valve and let it purge itself for a bit and then see if it behaves better. If that doesn't improve matters, then get a repair order going.

That was my first guess, about the debris, I mean. Getting this landlord to do anything about it is another thing.

What did the landlord say to you when you described the problem?

The building manager said that as long as the radiator was hot, I shouldn't complain.

This suggests that there are radiators not working in the building, which then lends further credence to the hypothesis that the steam pressure may have been turned up to try and force steam into the failing radiators...this I believe, is the most likely scenario..I do have another question, was the valve replaced when the radiator was, or did they keep the old one?

When the radiator was installed, a few years ago, a new shut-off valve and a new air-outlet valve were also installed. Everything was working perfectly until last week when the plumbers came to work on the boiler. As one of the responders suggested, debris from the work done on the boiler may have compromised the seal on the shut-off valve when the steam was turned back on on completion of the work. In any case, I just received a message from management that the plumbers are coming back to the building, probably tomorrow, and they will take care of all issues. We'll see how that turns out. I now have a lot more information about radiators and steam systems. Thank you for your input.

Well good luck then, keep us posted if you will....

Hi,

Thanks for the videos on repairing and maintaining valves.

Re: the problem with the shut-off valve on my radiator. A plumber arrived this morning, turned the steam off in the building in order to do some other repairs. I had closed the shut-off valve the night before so that the plumber could see that the seal was letting steam into the radiator even when the valve was shut off and to see what happened when it was reopened. After an hour or so, the steam was turned back on for the building. The plumber opened the shut-off valve on my radiator and everything worked normally. Air hissed out of the air valve and then shut off, the radiator didn't make any banging noises, the seal on the shut-off valve seemed to be doing it's job. Just turning off the steam for an hour seemed to have solved the problem. I was advised not to close the shut-off valve but just to open a window if the room became too hot. Opening and closing the valve had never been a problem until the work was done on the boiler last week. I will see how things work for the next few days. The young plumber did not seem to know anything about repairing the seal in a shut-off valve. Hopefully, that will not be necessary.

Well I'm happy to hear your problem has been resolved.....Gate valves with mechanical(metal to metal) seals are generally used in steam...the gate part of the valve is slightly wedge shaped and lasts a very long time with the operation of the valve actually keeps the mating surfaces smooth...they do become stuck sometimes in the closed position, which is probably why the technician recommended keeping the valve open...other than that the only maintenance required is the occasional tightening of the packing nut when water starts leaking around the stem...

Thank you again for the very good information.

After some years, the packing may harden from being progressively squeezed. If the valve is back-seating, opening it fully seals off the packing from the steam, so it can be replaced. If not back-seating, another valve may need to be closed, or the whole system idled.

Like SE, I'm glad your problem has been at least mostly solved, but...

"I was advised not to close the shut-off valve but just to open a window if the room became too hot."

That's ludicrous! It takes energy (costs money) to make that steam, and he's advising you to just throw away any excess heat. It might be wise to avoid shutting the valve tightly, but it is only logical to adjust it according to your need/preferences at any given time.

A one-pipe system entails two-phase countercurrent flow, which in turn may require the valve to be either fully open or fully closed. (This may depend on valve type and orientation.)

I have to confess that I was not familiar with the one-pipe steam heat system. To tell the truth, it may have been over 60 years since I last saw (or noticed) a steam radiator of any kind! I prefer not to go to large cities and large buildings, and of course we generally need less heat here in California.

I can't help but wonder if the young plumber's unfamiliarity with the standard valve repair issues is part of today's throw-it-away culture. With cheap valves from the Far East, if one fails, I suspect they just remove and replace it. I really hate that waste!

How does a two-phase counter current flow work? By the way, turning the boiler off for an hour and then turning it back on seems to have solved the problem.

In your case, steam (vapor) flows to the radiator, and water (liquid) back to the boiler. Two phases, opposite directions. This basically requires that even partly open valves need to leave some part of the passage open from top to bottom. This is what the design and orientation of valves accomplish.

To Tornado's correct answer, I'll add a few details that may or may not be obvious:

1. Water vapor is vastly lighter than liquid water (by a factor of very roughly 1:2000. The actual value depends significantly on the pressure). Thus vapor flows mostly upward, and liquid flows mostly downward.

2. Inside the radiator, the vapor (steam) condenses to liquid, giving its heat of vaporization to the metal, which then heats the room, and decreasing its volume by the large factor. This large decrease in volume makes it possible for more steam to enter the radiator, and means that only a trickle of water needs to flow down the pipe to the boiler.

3. In order for steam to rise freely, no part of the pipe can ever be allowed to fill completely with water. Thus no part of the pipe can slope downward at any point along its way from the boiler to the radiator. If the system was installed correctly, this is not a limitation; if not, a sagging pipe could cause very real problems.

For the last few days, the shut-off valve on the radiator has been open. Tonight I tried to turn it off and it wouldn't budge. It seems to be fused open forever. The heat is coming up full blast 24/7. Before the work on the boiler a couple of weeks ago, the radiator and the shut-off valve were working perfectly.

One possibility: The heat had been off when you last opened that valve, so it was cool. Then you (or the plumber) opened it fully. Since the valve was extended fully when cold, then when it got hot, it extended even more, jamming it open.

Try cooling the valve with a wet towel, possibly with some ice wrapped inside. If my hypothesis is correct, cooling it sufficiently should free it up.

DON'T FORCE IT! If you exert too large a force, you could break the valve stem or other parts, possibly with catastrophic results.

Good luck!

This morning I took a damp towel and wrapped it around the shut-off valve and was able to turn it completely off. In the intervening 3 hours, the radiator has cooled but is still warm, especially at the end near the shut-off valve. I guess it was just too hot to handle yesterday.

Oh good! At least you can get some control over your room temperature.

"...still warm, especially at the end near the shut-off valve." That probably indicates that the valve isn't completely closed. This could be due to blockage by debris in the valve, damage caused by debris that used to be in the valve, or pitting due to corrosion or cavitation. There is no way to be sure without disassembling the valve, and in your case, that sounds unlikely to occur. Do NOT try to do it yourself!

Thank you for your reply. Plumbers have advised me that steam radiators have to be all-the-way on or all-the-way off. I do, however, intend to shut mine all-the-way off from time to time. It was never a problem before last week's boiler work. I'm wondering if shutting the steam off for an hour today relieved the pressure on the valve, allowing water to drain out. When the steam was turned back on, the function of the radiator seemed to be back to normal.