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One supply valve effects other rads

Fizz Member Posts: 547
Richardson 2 pipe, vap/vac sys, with orifice supp valves.  One of rad valve either limits or shuts off 2 or 3 othe rads.  The suspicious rad does not over heat when open.  Nothing unusual in return pipe.  Currently, the rad is not heating tho valve is 2/3 open, supp pipe gets hot to 1/4 up to rad.  Afraid to adjust as all other rads are now working fine.  Wonder if I should wait til latter part of heat season to address it?


  • vaporvac
    vaporvac Member Posts: 1,520
    same Problem

    How do you know it's the valve limiting the steam to the other rads? i'll be interested to see how you resolve this as I have a similar problem.  Mine is on a rad on the 3rd fl bathroom furthest from the boiler.  The line feeding it from the mains and the rads directly below get hot.  SOMETIMES the bath rad does heat, but mostly it is stone cold along with the supply pipe. When I opened the valve, there was dissolved packing and no orifice, so I think maybe the steam goes straight on through.  However, that doesn't explain the cold supply pipes.  Have you checked your valves and orifices.?

    Mine heats on very cold days, so I also think  on not so cold days  the boiler doesn't stay on long enough to supply that radiator. All the others work,except one at the end of the line after going through the cold garage. Is your boiler staying on long enough and are your pressures low? That also helped mine.

    You can read the responses to my post last year as it may apply to your situation  IMine actually isn't fixed, but it is better.  I haven't yet addressed the orifices as I'm currently working on replacing the whole boiler.


    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • Fizz
    Fizz Member Posts: 547
    Supply valve mystery

    In answer to your question, i don't know if rad valve in question controls others, but when i move valve lever to off, rads worked, when opened they either shut or didn't get real hot;  now with lever 2/3, all work well except offending rad.  It may coincidence, it acts like steam in return line, but haven't seen other proof. I haven't checked orifices yet, i hope to, but may wait for heating season to wane.  Thanks for advice.

  • Al Corelli_2
    Al Corelli_2 Member Posts: 395

    You say your pipe runs through a cold garage. Is the pipe insulated?
    Al Corelli, NY

  • vaporvac
    vaporvac Member Posts: 1,520
    not on that pipe

    There is no insulation on the mains passing through the garage or the chauffeur's room.  I only noticed that last year.  Both rooms have ceiling hung radiators so I suppose they originally thought that would both heat the mains and the extra heat off the mains would be welcome.  However, we never turn those rads on as I currently don't have a chauffeur! Everything else was insulated at the time of the original install so I assume those were left uncovered on purpose.

    The bathroom radiator is Not the one after the garage so I still don't know the reason, unless the pressure is too low. Can it be too low on a vapor system?( It reaches about 1lb with a leaky boiler.) The rads on the 3rd fl, furthest from the boiler.Usually even the supply pipe is cold.  Once I get the new boiler I may try Fizz's approach of slightly closing the valves on the rad leading up to it.

    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • Steve_175
    Steve_175 Member Posts: 238

    Clearly your problem is you do not have a chauffeur. If you did, you could open those radiators, the system would be in balance and you would be driven were ever you wanted to go instead of insane. ;-)
  • Jamie Hall
    Jamie Hall Member Posts: 21,117
    Unlikely to be pressure too low

    especially on a vapour system, since they were designed to work on an ounce or so.  Two things to look at: first, do you feel heat in any of the return lines?  If so, you may have steam getting by somewhere.  This can do peculiar things; it doesn't always shut the whole thing down.  So that's one thing to look at.  However, for vaporvac, the other is the uninsulated lines and a possibly underperforming boiler (you mentioned a leak?).  It is just possible that those cold lines are condensing so much steam that there just isn't enough available (this applies to vaporvac's question).

    Another possibiity -- granted, it's remote but it's there -- is to check for any other valves on the mains or runouts, or to check for any place where there is either a restriction in the pipes or a place where the pipe size goes from smaller to larger.  There shouldn't be, but I've seen it.  With low pressure saturated steam -- like out vapour systems! -- sometimes such a thing will result in essentially no steam, or very little, getting by.  One system I worked on had a reduced port ball valve on a 3" steam main; even when it was open, there was almost no steam getting by.  Replacing it with a full port valve did the trick.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Rod
    Rod Posts: 2,067
    Two Pipe Steam System Oddities

    HI- You might want to read the following links on Gerry Gill's website to see if these situations might somehow be similar to yours:



    If you haven't been to his website before be sure to take a look around. Gerry Gill is a Cleveland pro who is an expert on steam systems.

    - Rod
  • neilc
    neilc Member Posts: 2,196
    check that trap

    if I remember my reading right then that rad with the valve affecting other rads ,,,,,

    its trap is failed open and the other rads on the same return are being pressure blocked by the steam leaking by ,,,,

    something to check
    known to beat dead horses
  • Fizz
    Fizz Member Posts: 547
    Moved suspected supply valve to 1/3 open

    Reduced suspected supply valve to 1/3 open, and now the 2nd floor radiator is not working and neither is suspected rad.  Suspected rad is part of original Richardson system which has no trap.
This discussion has been closed.