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Multiple issues with steam. Need a guru.


I just ordered Dan's book - We got Steam Heat and are finally trying to educate ourselves.

I also read Dan's Steam Heating primer. lots of interesting info.

We live in Yonkers, New York, just north of new York City. Our house was built in 1932. We bought it from a flipper who renovated the house. We are finding out that some of those changes have not worked out as well as might have been intended. Since purchasing the house we have made a few improvements - at least one a year.

Our house has steam heat. Our plumber, Derek, once mentioned that it was a two-pipe system.

Two years ago, we noticed a pinhole leak in a steam pipe jn the basement. Derek promptly replaced that section.

Next, two air vent valves started hissing loudly and spewing rust-laden steam when the heat came on. Derek replaced those valves and drained the boiler of built-up of rust.

The newly installed valves also had the same hissing issues. Derek felt the cause was incorrect/poor pitch of the return pipe to the boiler. Although he did not directly address the pitch issue, Derek moved the placement of the vent valves and installed new ones.

The new vents are still spewing rusty steam (darker than before) causing an unsightly mess in our basement. Could you help us fix this problem?

Additional info: About two or three years ago, we had our local handyman replace the ceiling in the basement. I don't think he paid much attention to the pitch of the pipe and may have inadvertently altered it.

We used to have a lot of water hammer. Since the most recent work, this has abated considerably. However, our heating costs this year seem to have zoomed up and we cannot find a good reason for this increase.

One reason we like our steam system is that it requires almost no electricity to keep the house heated. (And, until this season, the heating cost wasn't terrible either) We would like to install a reliable, cost-efficient way to ensure that the boiler keeps working in the event of a power-outage. We are looking at battery based inverters but are constantly being told that a generator is the only way to go.

I look forward to your solutions.


  • nicholas bonham-carternicholas bonham-carter Member Posts: 6,540
    the guru will be you

    have him look at the pressuretrol, which may be mis-set. depending on model, the settings should keep the pressure under 2 psi absolute max. no doubt the existing gauge will be inaccurate at the low ideal pressures these systems need, so get a 0-3 psi gauge from gaugestore .com, and mount it on s tee next to the pressuretrol.

    also pay attention to the main vents, and plan on improving those as well. pictures of the boiler will help.--nbc
  • BobCBobC Member Posts: 4,440

    verifying that the pressuretrol is set for 2 PSI maximum and taking pictures of the boiler and posting them here, you can check to see what pitch the returns have. Don't trust your eyes use a level and make notes about which way each return is pitched. The piping in steam systems has to be pitched right for the system to work.; it worked when it was installed so you will have to figure out what has changed since then.

    I assume some radiators seem to work ok and others don't, you have to see if you see what is different between the ones that work and the ones that don't. While your at it you might want to make yourself a diagram that shows each radiator and the supply and retuirn piping, note anything that seems different from the other radiators.Also note what order they branch off the steam main(s) and note the location of the vents.

    This may all be confusing at first but after studying how it's laid out things will start to make sense.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Jamie HallJamie Hall Member Posts: 6,693
    As NBC said

    you will turn into the guru.  Dan's books are tremendously helpful.

    Can you describe where the vents which are spitting are located?  Presumably on the steam mains in the basement, but at the ends or near them?  A sketch and some photos might help.

    Also as NBC said, pressure is very important -- make sure that it's right.

    That said, pitch is also important.  You need to make sure that all the steam lines and return lines pitch properly.  Dan's books have a lot to say about that, but the really fundamental idea is that any condensate which forms in the mains has to be able to drain freely back to the boiler, one way or another.  And any returns also have to pitch back to the boiler.  It really isn't rocket science; water only flows down hill.  So a place to start would be to check the pitch of all the lines you can find, and try to visualise what is happening to the condensate and steam inside them.

    On the power issue.  It's not impossible to run some types of boilers off of batteries and an inverter.  Most gas fired units don't take all that much power (some do: if it's a forced or induced draught unit, that fan takes a good deal of power -- see oil burners below), but many of them are sensitive electronic devices, and will require that the power be "clean" -- that is, a sine wave at 60 hz.  Not all inverters produce true sine wave power, and you would need to make sure of that.  I myself wouldn't try to run an oil burner off of an inverter, unless it was a really big one, as oil burners take a fair amount of power for the pumps and blower.  For those I would want a generator, properly wired -- and again make sure that it is delivering sine wave power.  Some of the newer, less expensive ones don't...

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • RodRod Posts: 2,067

    Hi- If you could post some pictures of your system it would be a great help. Take some pictures of your boiler which include the attached piping,boiler  (Take the pictures from back a ways so we can trace out where the piping leads. if we need more detail we can always zoom in.)  Also picture of one of your radiators and of your vents would be helpful.  You might also let us know the boiler's make and model. This information will be on a placard on the boiler. What is the maximum pressure your system is now operating ? How often do you need to add water to the boiler?  With this information we'll be abe to get a better idea of your system.

    - Rod
  • hshs Posts: 7
    A few photos and notes

    Thank you all for your rapid responses.  I'd love to be a guru but that takes even professionals years to get there.  I'll settle for a good understanding of my system and rely on a good contractor to get the job done right.

    I have added a few photos to get the discussion started. 

    It is a Williamson boiler with about the lowest EER - 81.9 AFUE.  See SpecsLabel for details.

    The spitting vents are Hoffman No.76 valves - actually one one is spitting.

    I measured the height of what i think is the return pipe - it is about 77" even from the basement floor.   Pitch appears to be an issue.

    The pressure was at Zero.  The heat was not on.

    The glass gauge has a lot of rust spots in it and maybe even some oil.

    We have an automatic water replenishing system so i don't know how often water is added to the boiler.

    The pipes all seem to flow into one another so I'll have to diagram them before i can make sense of them. 

    More photos and diagrams to follow.

  • Charlie from wmassCharlie from wmass Member Posts: 3,922
    check the pigtail

    the pigtail being clogged will not allow the pressurtrol to register so the boiler will run up in pressure wasting lots of fuel. Check the find a contractor section on the top of the page if you need a live body on site.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • hshs Posts: 7
    Live body wanted

    Yes sir, live body would be great.   Know any steam experts in the area?

    Don't have Dan's book yet, don't know what a pigtail is nor how to check it.
  • Charlie from wmassCharlie from wmass Member Posts: 3,922
    check the top of the page here

    Dan has a find a contractor section just to the right of the ask questions tab.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • kcoppkcopp Member Posts: 2,771
    Just from a quick....

    look your boiler needs to be cleaned, skimmed and flushed. Probably contaminated w/ the work that was done and not cleaned up after. The pressure looks to be set too high. No more than 2psi is needed. The boiler output is 521 sq. ft of steam.... how big in the house? that's a pretty big boiler...may be over-sized. What does the near boiler piping look like? another picture of the boiler w. the piping coming out would help.
  • hshs Posts: 7
    More photos

    More photos attached here - pipes coming out of the boiler.

    Yes, i would like to have the boiler cleaned, skimmed and flushed.  Also for the pipes.

    Would like to change /re-insulate the pipes.  I don't care much for that shiny stuff.

    I found photos of the pigtail, so i know what it is now.  Still wouldn't know how to clean it.  The pressure gauge reads about 6PSI when the heat is on.  it was on for just a few minutes and cut off.  a minute or so later, and the vent started hissing.

    The house is about 2100 SFT.  The boiler may well be over-sized. i would send photos of the radiators but they are all hidden behind grilles. 


  • BobCBobC Member Posts: 4,440
    Pressure too high

    Your pressuretrol is set much to high, steam systems operate best at low pressure - no more than 2PSI and hopefully less than that.

    Adjust the top adjustment screw so the tab on front moves down to 0.5 PSI 9just about all the way down. then loosen the screw on the front cover so you can remove the cover. Don't touch the wires but check that the white dial is set to one. That should lower the pressure from 6 to 2 PSI or less.

    The 0-30 gauge you have is not accurate at low settings but the system should operated better at low pressure.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • hshs Posts: 7
    edited January 2013
    I'll just wait for the pro

    I know so little about this that I am going to wait for someone to do come in and do everything.  At that time, I'll take some notes and try to be better prepared for the next time.
  • Boiler TalkBoiler Talk Member Posts: 125
    Wait for the pro

    Please excuse me now.

    The pressure is too high!  The gauge shows too much for your system.  One thing that will certainly help is lowering the pressuretrol setting as stated above.  Turn it down to .5 lbs. 

    Here's a second thought or perhaps the primary thought.  If you turn it down, if you trust your understanding of the numbers and I'm sure you do, then something will happen.  Right now you're wasting your fuel, but there are worse things.  Good luck. 
  • hshs Posts: 7
    Pressure lowered

    OK, I lowered the pressure. 
  • hshs Posts: 7
    Increased spitting

    After I lowered the pressure, it seems as if the the spitting has increased and a second air vent valve has started up - maybe because the first is all clogged up.
  • BobCBobC Member Posts: 4,440
    edited January 2013
    Bad for vents

    High pressure can damage or cause vents to become unoperative. Any vents that are not working right should be replaced with the correct size and type of vent. mains should be vented as fast as possible and radiators should generally be vented slowly. Overaggressive radiator venting can cause vents to spit because of all the condensate produced by the aggressive venting.

    Your boiler water should be clean, a light tan color is ok but there should not be any oil or debris in the water. The boiler may have to be skimmed and flushed to get the water clean.

    What kind of main and radiator vents are you using?

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
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