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New Boiler/Radiator Owner Here!

slayed Member Posts: 1
edited October 2022 in Gas Heating
I recently purchased my first house, a duplex in Jim Thorpe, PA. The heating system is natural gas water radiators. The fall has finally arrived and I turned the heat on for the first time. (Lots of first times!) I expected to hear some hissing while steam or air purged out of the valves, but it doesnt seem to stop.

I took some photos to show you what Im talking about, maybe someone can school me on these things. What does turning this lever do? Should the hissing stop? Do I need to replace these?


  • clammy
    clammy Member Posts: 3,015
    From the looks of the radiator valve and the trap on the outlet it looks like you have a 2 pipe steam system ,the air vent on the radiator is a band aide . Most 2 pipe systems do not have air vents there usually there on a main and either a air vent or cross over trap and a dry return main air vent or original air eliminator .a air vent on a two pipe radiator only indicates that’s there is a possibly issue w the systems venting . Usually this because as time went on and un educated on the ways of steam service people just added air vents instead of finding the issues . Usually a air vent is placed 2/3 up from the bottom not on the top of the radiator wrong location and a newbie mistake . You need to find some one is your area which is facials w 2 pipe steam systems and have them go over the system completely . What is meant by this is , checking the system piping and locating either main vents or cross over traps and ensuring they are operating properly ,check return pipe for main air vents and doing the same . Check all radiator traps for proper operating and making sure they are closing against steam and no pressurizing your dry return . Remove air vents from radiators and plug them . I would also have the boiler check to ensure it’s operating properly and is clean not loaded w mud ,check the pressuretroll settings but hopefully it’s a vapor stat clean sight glass, pressuretroll pigtail and low water cut off whether it’s a float type or probe either one should be clean and throughly cycled to ensure it’s proper function and that it shuts the burner off when either flushed ( float type ) or test button pushed , pull the burners and clean . Check your chimney base for blockage . Also not to be over looked is to have them pull the safety valve off and ensure that’s its piping is not loaded w mud and clogged see it all the time ,you need some one who is familiar w steam is required not just some plumber or heating guy that does heat you need some one who is familiar w steam other wise you may not feel they did anything . There’s other things to check and it would depend on the boiler age if it old then I would suggest filling the boiler to the top and check for any dripping water due to a hole in the boiler block . As things are I doubt you will find anyone cheap to perform these tasks and a lot will pretend to do but don’t just my personally experiences being there usually slightly messy and there’s more money in selling you a replacement t boiler . Peace and good luck clammy
    If they say keep the air vents please show them the door .
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • Jamie Hall
    Jamie Hall Member Posts: 22,100
    The vent shouldn't be there, as @clammy says. The question is, what was the problem that caused someone to put it there? It is possible that the trap on the outlet pipe (lower pipe) is not functioning properly. It's also possible that someone just didn't know what they were doing...

    The way that is supposed to work is that that valve you are looking at should regulate the amount of steam reaching the radiator, and therefore the amount of heat which it is producing. It may be VERY hard to turn, as most folks, once they get the radiator the way they like it, leave it alone.

    The vent hissing may suggest that the boiler is running at much too high a pressure. I suspect that that system should run well on half a pound or so.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England