non functioning radiators.

buckshot00

Hello all.  This site was recommended to me by a HVAC pro I know.  From what little I have read I am impressed!  So, on to my problem.

My building was built in 1925.  It is a 3 flat.  Radiators seem to be in good shape.  I have changed valves and vents as needed  Nice big boiler, gas fired, and probably over 40 years old.  The manufacturers sticker fell off long ago, so I am in the dark on that. There are 2 vents on the 2 main supply lines near the boiler.  The system has, for the most part, run well since I bought the building in 1986.  My issue is this:  there are 2 radiators in each living room.  Last year the radiators on one side of each living room quit working.  All 3 are on the same side of each living room.  I thought it was the vents, so I changed them out.  Not the solution.  So I am at a loss as to what else it could be.  A trapped air pocket?  If so, how do I go about bleeding it off?  Any and all advice would be appreciated.  Once we get this taken care of, I will have some other questions to ask.



Thank you in advance.

Rod

Need More Info

Hi- Just to check the info we have. This is a one pipe steam system? Are the non working radiators on the same steam main?  Do the steam mains have return piping?   Pictures of the non working radiators and the vents on the steam mains would be a big help. Was any renovation /remodeling work done that could have disturbed the piping?

     I would check the operation of the main vents first. Do this by taping a strip on newspaper on the end of a broom handle and hold it near the orifice on the vent.The paper should move as air is being released and than shut off when steam reaches the vent. Don't test vents using your bare hand. Live steam can give you a bad burn!  More information will help us narrow down the source of the problem.

- Rod

BobC

How long

To add to what Rod has said, how many steam mains do you have in the cellar and how long does it take steam to reach the end of each steam main? Perhaps one of your main ar vents on the main has stopped working as Rod mentioned.



Do all these problem radiators come off the same area of the same steam main?



Bob

buckshot00

Non functioning radiators

First off: thanks for the quick responses Rod and Bob.  I have been told that it is a 1 pipe system.  All 3 radiators are supplied from the same main, I believe, as they are one above the other on their respective floors.  That is why I believe one problem has affected all 3 of them.  I am not aware of any other main vents, aside from the ones I can see and that have been replaced in the last few years.  As Rod suggested, I will check then per his instructions and let you know what I found out.  Could 1 of these vents not functioning effect just these 3 radiators and no others?  Not even the pipe up to the shut off valve gets hot on any of the 3.



The radiators themselves are heavy cast iron.  Just under 4' long, 12-14" wide and about 2' tall.  



Thanks again for any help.

Rod

Radiator Problems

Hi - Are there other radiators on the same main as the non functioning radiators? If so, are they working satisfactorily? If there are other working radiators on this main are they closer or farther away from the boiler than the non functioning radiators?

What is the make and model vents used on the non functioning radiators? You might swap one of these vents with a vent on another radiator that you know is good and working properly. (Be sure to do this with the boiler off and when it has cooled down a bit.)

- Rod

buckshot00

non functioning radiators.

I will look and get back to you on the vents.  I did do a change out of at least one of them when the issue first arose.  Yes there are other radiators on this main that work just fine.  My un-educated guess is that the line that supplies all 3 radiators is where the issue is.  My understanding of the system suggests that these are all on the same riser.  I keep going back to the fact that all 3 radiators are  in the same location on the 3 different floors.  Would all 3 vents cease working at once?  There has been no major work done to the system or the building involving the heating, other than regular maintainence and valve and vent changes when needed.



Thanks again for your help.

Hap_Hazzard

Pictures?

Could you possibly post some pictures of the piping to the affected radiators?



While you're at it, if you could post a few of the boiler one of the pros here can probably identify it, in case you're curious.



What happens if you close the valves on some of the radiators that work?

buckshot00

non funtioning radiators.

Let me see about the pics as I do not have a scanner (old computer).  I will also try the valve thing to see if that makes a difference.



Thank you.

Rod

Hog Radiators

Hi- Some of our questions may seem a bit weird as what we are trying to do is eliminate certain possibilities, Why Hap is suggesting that you close the valves on the "working" radiators on the same steam main as the non functioning ones, is that in some situations, the radiators that are working may be "hogging" all the available steam. This can cause other radiators on the same steam main to "starve" ( not get steam and therefore not heat up) If closing down the radiators on the same main doesn't  get steam to the non functioning radiators, try also closing some of the large radiators that on the other steam main, especially the ones closest to the boiler.

The cure to "hogging" is high capacity venting on the steam mains and to use slower vents (lower venting capacity) vents on the radiators especially the hogging ones. This is why we are curious to what the make and model of the radiator vents you are using now.  Increasing the main venting capacity and using slower radiator vents, helps distribute the steam more evenly between the radiators and helps prevent “steam hogging”.   Try this test out and if it doesn’t make a difference we can go on to other possibilities.

- Rod

buckshot00

Non working radiators.

First off, thanks for the explanation of the questions.  As to shutting off the working radiators valves, I will give that a shot.  I think they are supplied by different risers.  I can see some of the pipes in my basement, and there is a supply going up each side of the room for those radiators.  I have a hard time getting to the pipes (long story!), and they are covered with insulation, so I do not know if they are both hot, at least in the basement.  I will get at them in the next day or 2 and peel the insulation off and go from there.  I am confident that with all of  your professional help, we will get to the bottom of this.  I will take some pics and see if I can post them right from the camera, as I do not have a scanner.



And as always, thanks for taking an interest and for all of your help.  It is appreciated.