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One pipe steam system - unbalanced

I bought a house over the summer built in the 30s and located in NJ. All of the radiators except 1 were functional during the inspection, but it was a quick test. Now that I'm living here, I found out that the one radiator that didn't work simply had the valve turned off. I turned it on and have some issues:

1. The radiator that was turned off has steam leak out of the vent(Hoffman 1a).
2. Two rooms barely get any heat on the second floor. Two have Hoffman vents and one of these had steam coming out after I turned up the heat high so that all radiators became hot. This one was level and I raised the vent slightly so it drains.
3. There are 2 radiators near the thermostat and this room gets warm fast. Both have a Jacobus maid o mist vent, but I am not sure the size. The hole feels somewhat large.
4. I do not know where he main vent is. I cannot seem to find any near the boiler.

First thought is that I should change the vent on the 2 radiators near the thermostat to a Hoffman 1a or a vent with a small hole so it will not fill quickly.
Should I run the system several more times to see if steam always comes out the vents that had the issue? As these are on the second floor and do not heat quickly, I want to add a large vent.

Lastly, I've emptied a bucket or 2 from the boiler several dozen times and try not to do to much at any one time, but the water is black and does not seem to improve. I don't know if the previous owner ever did this. I know they never cleaned any of the radiators!


  • Paul48
    Paul48 Member Posts: 4,469
    There are some excellent steam pros in NJ. At this late stage in the game (getting colder), you might want to bring one in for a consult.
  • Jamie Hall
    Jamie Hall Member Posts: 22,877
    I agree with @Paul48 there -- there are some really good guys in your area.

    But. Until then (if then!), the first thing to do -- the very first -- is to go down to that boiler and check the pressure settings. Chances are that your control is a pressuretrol. The setting on the front -- if that is what it is -- is the cutin pressure. that should be around .5 to .75. (It really should be .5, but pressuretrols can be a bit squirrely if set as low as they can go, so I'd go a bit higher on it). Then inside the control is a white dial. That should be set at 1 -- that's the differential. The combination will hold your steam pressure below 2 psi -- which may solve the spitting vents without doing anything else.

    The main vent(s) if there are any will be on the ends of the steam main(s) -- not near the boiler. I wouldn't be all that surprised if there weren't any, and that is something which you will want to correct. We can help size them, or a pro can do it easily.

    Balance in one pipe systems is just that: balance. if the vents with steam coming out still misbehave with the pressure set right, it will have to be replaced. That shouldn't happen. Otherwise, it is usually -- not always -- best to slow down the radiators which get too hot too fast, rather than trying to speed up the ones that don't. Unfortunately, every change you make affects everything else, so it can be a bit tedious.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • adambnyc
    adambnyc Member Posts: 260
    Take some pictures of your boiler and the piping connected to it.
  • Steamer_2
    Steamer_2 Member Posts: 2
    I did some more looking around at the pipes/vents and do ant to have a professional come look and check out the whole system.

    Can anyone recommend someone near Westfield NJ?

  • Paul S_3
    Paul S_3 Member Posts: 1,257
    edited November 2016
    You can give us a call @Steamer
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    [email protected]
  • ChrisJ
    ChrisJ Member Posts: 15,433
    @Paul S Does beautiful steam work.
    He's one of the best.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    Paul S_3