Steam radiators pipes banging. Help!

NFER

Hi,

This is my first winter in a rented apartment with one-pipe steam system and so far it has been terrible. There are two pipes with their radiators that bang day and night. The plumber has come several times in the last two weeks but it seems he does not get with the solution. And now he is saying there is no noise when he turns the system on. Something that it is not true.

My wife and I are desperate because the noise is waking us up at 3.30am every morning.
I hope guys you can help me to find where the problem is.

It is a small apartment with 4 radiators and raisers. I am in the level above the boiler and there are two more floors above my apartment.

• The first radiator getting hot does not bang but the vent is open during all the cycle releasing air. But it seems that the radiator is getting completely hot very fast without any cold zone. Where is the air released by the vent coming from?
  
  
• Second radiator and pipe getting hot bang. First the pipe a little bit and then the radiator as soon as the vent is closed. The radiator pitch has been checked.
  
  
• The third radiator getting hot does not bang but the vent is open during all the cycle releasing air, a lot of air. But it seems that the radiator is completely hot very fast without any cold zone. Where is the air released by the vent coming from?
  
  
• The forth radiator and pipe getting hot bang. First the pipe a little bit and then the radiator as soon as the vent is closed.
  
• The radiator pitch has been checked. The plumber changed the vent for and Danfoss valve with a Gorton C on top. But it is the same, as soon as the vent is closed the radiator starts to bang.
  

I am far from being an expert but I think that the pressure is quite high and that is why the vents are releasing air during the complete cycle. I asked the plumber what pressure the system has and he told me the normally keep the system with 5 psi. I said that 5psi is too high and he has lowered the pressure. He did not tell me the new pressure value. After that the radiator number two and four are banging less.

The plumber is going to visit the apartments above mine this Friday and check the pressures, vents and radiators.

What else can I do?

Paul48

Put a level on top of the radiators that bang. They should pitch, ever so slightly towards the valve. If not, put quarters under the legs farthest from the valves. Maybe a couple bucks fixes your problem. Five psi is ridiculously high. Those systems can run on ounces, in the hands of someone that has a clue. Tell the plumber that this site is here to give him any support he needs. He has access to steam pros and manufacturers, all willing to give him a hand sorting out issues. Make sure the radiator valves are fully open.

NFER

Thanks for the comment. Yes, I put shims below the legs at the vent side of the radiator and the pitchs are correct.

Can the radiator bang because of the high pressure?
And the noise in the pipes can they also be related to the high pressure or can they be due the bang of radiator above my apartment?

I am trying to understand what happens to a raiser and radiator when is full of steam and the pressure is too high (like 5 psi).

adambnyc

Can be a whole combination of things. The boiler sounds like it's surging, which means it's pushing water up into the pipes instead of steam.

The banging you are hearing is the steam colliding with water in the pipe.

Since your not the owner and only the renter, your at somewhat of a disadvantage in terms of getting this fixed.

You can pitch and fix the Rads in your apartment, but you are very correct that the banging could be coming from pipes that supply other apartments.

Your landlord would need to call in a steam expert to review the issues and remediate them.

It could be as a simple as the boiler water is very dirty and needs a good cleaning. Or it could be that the entire boiler needs to be plumbed over again. Recommend that they skim and clean the boiler water and see where that gets you.

Ironman

Air is drawn back in the system through the vents when the boilers shuts off and the cycle ends. It's a normal part of one pipe steam operation. What's not normal is the banging.

Anyone who would run the system at 5 psi does not understand steam. Getting here to get help would be good, but he's not not gonna pick it up overnight - if he's willing to get help at all.

The best thing would be if the owner would come here and get one of the steam pro's listed on this site.

Where are you located?

NFER

Thanks for the response
In New York.

My point is if the radiator is full of steam and there is no cold air inside. What is the vent releasing? hot air from the condensation of the steam to water?
In a correct system when a radiator is full of steam the vents are closed, arent they? is not there hot air from the condensation that should be released anywhere? where does it go?

RomanGK_26986764589

You vents are releasing steam. They are not supposed to do that. They are probably shot due to high pressure and need to be replaced. High pressure ruins vents very quickly.

Fred

If the pipes are banging, there is a good possibility that there is a length of horizontal pipe under the floor, especially since you are on the first floor. Shim the valve end of the radiator up a bit and then re-pitch the radiator back towards the valve. That may raise the pitch of the horizontal pipe, back towards the boiler, enough to allow any condensate in that pipe to drain. The vents are likely going to vent as long as that system pressure is as high as it it. The pressure controls are on the boiler, typically a Pressuretrol. It needs to be set at .5 PSI on the front scale witha differential of 1 PSI. If it is a Gray Honeywell Pressuretrol, the differential wheel will be under the cover. Iwill be white. The "1" should face the front of the box. If it is set that way, the pigtail (looped pipe) under the Pressuretrol may be clogged with gunk and need to be cleaned out.

Mad Dog_2

There are several REALLY good guys that advertise here on FIND A CONTRACTOR. any one of us can help you with a field visit. Take yer pick! Mad Dog

JUGHNE

Positive point for your plumber that he agreed to turn the pressure down without the usual comment "it is a big building and needs a lot of pressure". Of course he may not be sure of how to do it.

If you point out to him to advise the owner that the high pressure will wreck the rad vents and cost him money, the owner may take heed from the plumber rather than the tenant.