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Questions about my Steam broiler


I have a old steam broiler that I want to service/ run yearly maintainence on. I did some research on the internet and figured out the basics. but I am confused about few things. for starters, my broiler has multiple valves to drain it and I am confused which ones to use. I know I have to drain the broiler tank (1) and the pipes (3,4). but what is valve 2 for. please see pictures for reference.

And also what is this Honeywell device connected used for ? it seems to have a setting on it but not sure what/how to use it for. is it used to increase or decrease the steam pressure PSI in the system ? and lastly the end cap nut in the broiler. what is it for ? is it for a waterline or is it a inlet option to dispense cleaning chemical or is it something else. and lastly on the other side of the broiler there are 2 more outlets. one is a valve and the other seems to be a long pipe to a control valve or what ever its called. Please help me understand the setup and successfully service this broiler.


  • SteamingatMohawk
    SteamingatMohawk Member Posts: 840
    Based on your information, I implore you to get someone who actually knows something about steam heat to do the first "maintenance" and teach you. Better safe than sorry.

    While HH is a great resource and there is lots of information available, there is no substitute for real, credible experience and face-to-face learning.

  • jhewings
    jhewings Member Posts: 139
    edited October 2022
    "2" appears to be an elbow under the low water cutoff ( the large black device above it). The most important valve here is the yellow one attached to the low water cutoff. The low water cutoff is the most important safety device here. You should be opening that yellow valve every week or two to flush out the low water cutoff. Leave it open until the water looks clear. If you have not been doing that you must start immediately. Open that valve when the boiler is running. The boiler should stop. When you close it the boiler should start again if there is enough water in it.

    You should consider reading some of the books at the store here, such as "We got steam heat". Since you are just starting to learn you should consider hiring a boiler company to do the service this time.

    I don't see a pressure gauge and I'm wondering if the pressure release valve is mounted to a pipe that is below the water line and if that is ok. Others here can comment on that.
    EBEBRATT-Ed Member Posts: 13,760
    First picture is a "skim valve" it is closed know and is opened to skim oil or other debris from the top of the boiler water

    Second picture is the high limit steam pressure control. It shuts the boiler off on excessive steam pressure
    spare inlet is just a spare boiler tapping that is not being used. Some boilers have xtra tapping as they can be used for water or steam

    Third picture #2 is a drain from your low water cut off. this control shuts the boiler off to protect the boiler if the water level gets too low.

    #1 is just a drain to drain the boiler, #3 drains the equalizer pipe to flush out sludge #4 is a drain on your dry returns again to flush out sludge.

    Any of these valves could fail if they have not been opened in a while. You might want to have spare valves on hand or at least some garden hose caps (from big box or hardware store) on hand in case the old valve(s) leak
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 840
    If you insist on DIY, at least, get the boiler manual for that model so you can better understand the system. BUT, bear in mind lots of times the systems are not assembled "by the book".
    I still stand by my initial recommendation.
  • random12345
    random12345 Member Posts: 469
    edited October 2022
    I mean no offense but I thoroughly enjoyed your use of the word "broiler" to describe your boiler.


    I suppose if you removed the top part of the jacket and its insulation the cast iron top of the "broiler" could be used for cooking, but only as a griddle, and only when it's steaming. Placing food underneath the "broiler" probably wouldn't work. I don't think the food would cook. Your young chicken does not look so very young.
  • MaxGNaidu
    MaxGNaidu Member Posts: 15
    edited October 2022
    Thank you everyone.. I have decided to follow your advise and hire a heating expert to do this one. I have heard quotes ranging from $$$ to $$$ for a full drain and chemical treatment along with some health checks included.
  • ScottSecor
    ScottSecor Member Posts: 721
    We are not allowed to discuss pricing on HH. However, I think you hiring a professional will be money well spent!
  • clammy
    clammy Member Posts: 2,981
    That boiler has to be over 30 years old at a minimum , I would think it would be due to a wanding to remove mud and rust build up in the bottom of the boiler aside from disassembling and clean the float low water cut off and cleaning of the pigtail for the pressuretroll . A check of the safety valve piping for being plugged quite common . Most likely it needs a good maintaince servicing as do all things . If replacing make sure they measure and do a edr Calc to ensure they do not oversized and that all new piping is in steel .usually from my experiences they seemed to always oversize steam boiler back then and even now some do by accident
    Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 840
    Try the find a contractor app at the top of the discussion.

    Where are you located? The guys on HH are a good source for reliable contractors.
  • MaxGNaidu
    MaxGNaidu Member Posts: 15
    edited November 2022
    Okay, here is the update....based on the advise on this forum I decided and went ahead to hire a contractor to do the job. He quoted $. He came took a look at the system, said it's too old and he doesn't want to shock the system by adding any chemicals to clean it. He suggested a simple drain and refill will suffice and also he opened up the glass water level thingy and cleaned it. And that's it...I feel like, based on what he did. I just wasted my money...lol. but overall he did give me some knowledge. so, I think it made it up for that I guess.
  • MaxGNaidu
    MaxGNaidu Member Posts: 15
    And oh yeah for the drain and refill....he just used valve 2. He didn't even touch valves 1,3 and 4 at all. Is that the right way ? 
  • mattmia2
    mattmia2 Member Posts: 8,377
    No. That is for flushing/testing the low water cutout. there is water in the boiler below that which you would have to use the other drains to drain or flush out.
  • 109A_5
    109A_5 Member Posts: 826
    Hello @MaxGNaidu,
    In my opinion now that we are into the heating season the only two valves I would use is the Yellow handled one on the McDonnell & Miller No. 67 Float Type Low Water Cut-off (LWCO) and the Yellow handled water inlet about once a week.

    If you mess with any others valves now they may leak requiring repair. You don't want lingering leaks that cause you to constantly put extra fresh water in your boiler. If you can change the valves yourself or you are willing to pay a plumber to do it than tinker away.

    I would wait for a time when the situation would not be so dire, like in early Spring. Come Spring go over the whole thing, give it a good cleaning and flush, repair or replace any valves that don't survive. Run it a bit more to boil out the oxygen for the Summer recess.

    Ideally all the valves should work correctly all the time to purge the Mud and contaminants from the system as needed. Also it minimizes accumulation on the bottom of the boiler. Clean water makes drier steam, more efficient for your system, less fuel used.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System