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A lot of steam coming out of radiators

chimmy Member Posts: 1
edited February 2021 in Strictly Steam
Hi! New homeowner, my first post here. Really could use some help.

1 pipe heating system in a recently-purchased but really old house. We have a combo system - water heater and boiler 2 in 1. The age of the boiler is unknown but AT LEAST 20 years.

Our heat is fine except one thing. The bedroom heater is ALWAYS letting out steam. It's annoying but bearable. There is steam in the bedroom 24/7, making it a sauna room everyday. I have always thought it's a problem with the valve. Today I finally decided to change the valve. And here's how the story began.

After changing the bedroom valve, it is working fine. Heat is coming quietly and nicely. No steam in bedroom. However, steam is coming out of living room valve. A **** ton of steam, so loud that we couldn't hear each other talking.

I went to the boiler room to check the main valve. The main valve model is Bell & Gossett NO.7 2106512-2276136 Auto-vent 1/8in Threaded Valve B279823. The main valve seems to be have been closed by the previous owner. When I tried to open the main valve even just by a little bit, water comes out of the vent. brown and hot water. I got scared and turned it off.

I'm completely lost at the moment. What should be my next step?

Recommendations of steam heating exerpts in NYC area highly appreciated.


  • mattmia2
    mattmia2 Member Posts: 9,629
    Some pictures would be good. The b&g valve appears to be a hot water automatic air vent. It would either be on some sort of hot water loop either for dhw or an add on hot water heating system or be an incorrect vent for steam.

    What is the pressuretrol set to? Sounds like it is way too high.
  • ethicalpaul
    ethicalpaul Member Posts: 5,701
    It sounds like your pressure may be too high and/or your near boiler piping is badly designed and is putting boiler water into your main.

    you can reach out to @JohnNY for service in NYC
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • KC_Jones
    KC_Jones Member Posts: 5,737
    Pictures would surely help. I am not sure how one turns off a main vent, so I am genuinely curious. I agree with @ethicalpaul there is something amiss with pressure or piping. Could also be a clogged pigtail leading to high pressure.

    I just looked and if your main vent is what it seems then that is for a hot water system and has no business being on your system. Post a picture of that for verification.

    Couple general points. Steam should never come out of a vent, if it does the vent is bad and needs replaced. If the pressure is running high, that can destroy vents. If that is what is causing your vent failures then the pressure is certainly first on the list to address.

    Again pictures will go a long way to us assisting you. Pictures of the boiler and piping. Pictures of the pressurtrol will tell us the setting.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    EBEBRATT-Ed Member Posts: 15,516

    Pictures will help. Some question if this is steam or water. I would contact @JohnNY check "find a contractor" on this site