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Need Advice - Single Pipe Steam System - Boiler Issues

Ben_2 Member Posts: 10
I recently purchased an old house. With it came lots of plumbing issues that I am working through, like a cold water lead off the Well pump that loops back to itself (if this makes sense to someone else I could listen to why, it makes no sense to me but oh well.).

The issue I could use a lot of help with is the Oil Boiler that heats the house through a single pipe Steam Radiator system.

If I use incorrect terminology please correct me. I'm a computer tech guy who built houses for a living in my past life, so I'm not afraid of the home electrical and plumbing jobs as long as I have the right tools and knowledge. I can buy the tools and I hope to suck the knowledge out of anyone who will allow me to.

So let's get to the point. I know next to nothing about steam boilers, aside from what I've been reading on the web and apreciatively on this site. I am sartig basically from scratch and would like to ask quite a few questions that hopefully someone can answer for me.

Question one:
It seems that my boilder likes to 'overload'. What I mean is it has what I assume is a pressure relief valve on one side that shows clear singns that it has been blowing out steam for quite some time. The valve point towards one side of the chimney that the boiler uses, this area is covered in rust stains. I recently witnessed this blowout, which was quite loud and filled my basement with steam, enough to fill it and come up the stairs into the kitchen. I'm smart enough to know this is most likely due to too much pressure in the system (hehe), but I don't know how how to effect a change. Another thought is that the valve is old and needs replaceing, but hey I'm a network guy.

The problem is I'm a network guy who just paid a plumber $700.00 to do something I am more than capable, and willing to learn how to do.

So instead of rambling on unprepared I'm going to end it here. But I will be back with the model number of my boiler hopeing someone can point me in the right direction for maybe a manual for the old boiler (I'm a firm believer in RTFM). If not maybe I can post pictures of all the gages and adjustment equipment on my boiler and maybe someone can lend me some knowledge. I am MORE then willing to exchange puter tech knowledge on a site of choice or even through direct email.

I know the price of knowledge I just can't currently afford it in cash. You all know what heppened to the 'dot coms'? I'm a victim of that whole fiasco.

Your willing pupil.

Ben Todd
Mont Calre PA
House picture link


  • Jamie Hall
    Jamie Hall Member Posts: 22,949
    you've come to the right place

    believe me. These guys are great!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • joe_14
    joe_14 Member Posts: 138

    Hi Ben;

    sounds like your pressuretrol is set to high or it is not working properly.this is a little gray box that is attached to a curly-Q piece of pipe(we call this a pig tail).most of these are made by honeywell.if you take the cover you will see two scales one is called cut-in this should be set at.5(half pound)the next scale is your differential which should be set at 1 psi.this means you boiler will cycle between .5and 1.5 psi thats all you need to heat your house.

    if this is set ok shut off boiler make sure pressure is down. take this box off the pigtail and take pig tail out of boiler somtimes these become plugged with dirt and crud . try to blow thur pigtail if cant take a piece of wire and force it thru pigtail this is hard to do so be paticence. keep doing this until you can blow thru it easily. rinse out pigtail and re-assemble pigtail and contol back onto boiler. this should stop the over pressure problem. if not you may need to replace control(gray box.

    good luck
  • Ben_2
    Ben_2 Member Posts: 10

    Mine is a Honeywell. It's wired directly to the Emergency shutoff.

    The Cut in was set at 8psi or .6 KG/CM (Kilograms per Centimeter?) and the Cut Out was set to 2 1 being the lowest and 5 the highest (a small weal attached to what looks like a spring swich. I assume what's meant to happen is pressure builds in the boiler as it reaches the high point and pushes through the pigtail it pushes the spring switch enough to shut the boiler off using the same power in the Emergency cutoff switch. I also have to assume that either the Pressure relief valve that is pouring steam into my basement is set lower than the switch or the switch is not working at all, (pigtail blocked or the like)

    I am one to replace things I am not sure off. When I looked at this box I saw it was wired to the Emergency Shutoff and connected to the Boiler through the PigTail. The pigtails attachment to the pressuretrol is obvious but not so obvious to the boiler. The way you describe it, it simply slides into the boiler. Or does is thread in?

    How much do these things usualy cost and are they specific to the boiler, i.e. should I bring mine in when I go to buy the new one?

    Thanks For your time.

  • joe_14
    joe_14 Member Posts: 138

    The pigtail is treaded into the boiler.The pressuretrol is wired in series with the low water cut-off,these are your safteys.From your last post you need to re-set your pressuretrol as i explained in my first post.
    Iam not sure what a new control cost,maybe around 50 bucks, Iwould also replace the the relief valve. this is a 15lb 3/4inch steam relief, cost around 50 bucks.

    Before i do this i hope you tried what i explained in my first,about cleaning pigtail. good luck
  • Ben_2
    Ben_2 Member Posts: 10
    I haven't yet

    I haven't done moren than make the adjustments you suggested. I haven't seen the problem yet, but then again the system hasn't cycled more than once yet. Once I remove the pigtail for cleaning should I use a teflon tape when I put it back?

  • Yes , use some Teflon

    on the threads of the pigtail . If you decide to replace the pressuretrol , pick up a new pigtail also - theyre pretty cheap . And also change the boiler relief valve - if it was blowing off alot chances are itll need to be replaced . The spring in the relief will wear and get hit with rust . Better safe than sorry . Also make sure to put a relief pipe in it and bring it close to the floor - I got hit with live steam on my arm once and it didnt heal for a few months . Good luck .
  • Steamhead
    Steamhead Member Posts: 16,736
    That's a beautiful house

    and the steam system can run just as beautifully. You've come to the right place.

    That Pressuretrol should be cranked all the way down. Your system was designed to heat the house to 70 degrees at the lowest outside temperature expected in your area, with no more than 2 pounds of steam in the boiler. A stiff wire, with a small Vise-Grip firmly clamped onto it, works great for cleaning pigtails.

    If you're having trouble getting steam to the far ends of the system, you likely need to install (or upgrade) vents on the ends of the steam mains. These are crucual to proper steam distribution and fuel economy.

    If you haven't done so already, get a copy of Dan's book "The Lost Art of Steam Heating", available on the Books and More page of this site. This is by far the best book I've seen on the subject.

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Ben_2
    Ben_2 Member Posts: 10

    > If you're having

    > trouble getting steam to the far ends of the

    > system, you likely need to install (or upgrade)

    > vents on the ends of the steam mains. These are

    > crucual to proper steam distribution and fuel

    > economy.


    I'm glad you brought this up. I've been doing a ton of reading on this site and have read quite a bit about vents on the ends of mains. Now I figure I got the vents part down. Each one of my radiators has a vent on it.( Except a few and they don't work too well. I understand what they are for, as the steam moves up the single pipe system, the air n the system needs to go somewhere to make space for the steam.(simple dynamics). I am assuming that the vents at the end of the mains will do something similiar. My lack of knowledge is in the 'mains' part. Anyone have a picture they could show me of a vent at the end of a main?

    > If you haven't done so already, get a

    > copy of Dan's book "The Lost Art of Steam

    > Heating", available on the Books and More page of

    > this site. This is by far the best book I've seen

    > on the subject.

    I have also read quite a bit about this book, so I'll break down and buy one. Then maybe you guys won't have to answer all my inane ignorance based questions.
This discussion has been closed.