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Sudden difference in main line heating

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For a few months both my mains (short /long) would heat about same rate,  meaning radiators would fill on either main fairly close in time.  Now, with nothing being changed,  the short main takes much longer to heat and the all the radiators on the long will fill before the short gets going.  What would cause this sudden change? I can still hear the the short line vent venting, so it's not clogged.

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  • Steamhead
    Steamhead Member Posts: 16,832
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    Dirty boiler water?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    ratherbfishing
  • ethicalpaul
    ethicalpaul Member Posts: 5,702
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    Start a call for heat and use your hands to see where the steam is traveling. See if both mains get steam to their main vents at the same time. If so you'll know you can look beyond the mains.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ChrisJ
    ChrisJ Member Posts: 15,671
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    For a few months both my mains (short /long) would heat about same rate,  meaning radiators would fill on either main fairly close in time.  Now, with nothing being changed,  the short main takes much longer to heat and the all the radiators on the long will fill before the short gets going.  What would cause this sudden change? I can still hear the the short line vent venting, so it's not clogged.


    Are all of the radiator vents on the short line clear? Any water droplets in them? I'd start by blowing into each vent with a can of air including the main vent(s).

    Anything sagged? Holding water?

    Did you change any vents on the longer line?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Main vent on the long gets hot first. Didn't change anything.  

    Dirty water? I did notice this about the same time the pigtail was gunked up.  Cleared that but didn't change it.  After i had the system served in December it was operating so nice.  So maybe dirty water ( it is very dirty) but how would that change it?
  • ethicalpaul
    ethicalpaul Member Posts: 5,702
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    If there is boiler water getting to one of the mains via surging, that will kill a lot of steam there. How's your water level during firing? How's your near-boiler piping look?
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Water level is good,  it's not on an auto feeder so doesn't get over filled. I suppose I could try and flush it out and see if that magically does anything.  For curiosity sake,  I switched out one of the gorton 4 s at the end up the short line with a varivent open at full.  Can really hear the air coming out but didn't speed things up on that line
  • ethicalpaul
    ethicalpaul Member Posts: 5,702
    edited February 2023
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    I didn't mean the general water level, i meant during firing does the level drop noticeably? That would be an indication of surging.

    I wonder if one of the radiators on your long line might have a large capacity vent that is stuck open and stealing the steam from the other main. Check for that.

    Then if not that, I guess I'd put my hand on every radiator valve on the "cold main" to see if/when the steam gets to each one to try to find what's up.

    You should be able to put a large, fast vent on one of the radiators on the "cold main" that will make that radiator heat up. If it doesn't then you know something is really up.

    The important thing to remember is that the steam is going where it's easiest to go. So something is either making it real easy on the one main, or real difficult on the other main for the steam to go there. That's all there is to it.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Thanks for suggestions.  How would surging affect main line heating?
  • ethicalpaul
    ethicalpaul Member Posts: 5,702
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    Because if boiler water is getting sent into the main piping, it can "kill" the steam
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    ratherbfishing
  • PC7060
    PC7060 Member Posts: 1,159
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    Do you have a vent on the short main that’s not opening?
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,519
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    Watch the water level when it is steaming? It shouldn't bounce more than an inch or so.
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    PC7060 said:
    Do you have a vent on the short main that’s not opening?
    I don't think so,  all of the rads heat up

  • ChrisJ
    ChrisJ Member Posts: 15,671
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    Oil or gas?
    If gas please clock your gas meter with only the boiler running.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • dabrakeman
    dabrakeman Member Posts: 552
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    I'd double check the main vent on the slow main. If it is not open the radiators will still heat up, just much slower.
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    I decided to flush the boiler as recommended above. I was draining from bottom valve of sight glass and noticed it wasn't terribly dirty and running clear pretty quickly.  So i stopped draining, just cleaned the sight glass, filled about 1/2 sight glass full of water to restore water level and turned on system.  Huge difference.  The short main heats up much quicker now,  similar to previous.  It seems to have fixed it,  but I'm super confused why that worked. 
  • ChrisJ
    ChrisJ Member Posts: 15,671
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    I decided to flush the boiler as recommended above. I was draining from bottom valve of sight glass and noticed it wasn't terribly dirty and running clear pretty quickly.  So i stopped draining, just cleaned the sight glass, filled about 1/2 sight glass full of water to restore water level and turned on system.  Huge difference.  The short main heats up much quicker now,  similar to previous.  It seems to have fixed it,  but I'm super confused why that worked. 

    Oily water tends to get blown up into the piping more.
    This can cause big issues.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    ratherbfishing
  • BobC
    BobC Member Posts: 5,477
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    If thoseproblems come back in a few fays it means you have oil in the boiler water. That ca;;s for a couple of long skimming sessiond to float those oils out of the skim port.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 1,005
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    Serviced the system in December, worked OK, now its not. Apparently there's oil in the boiler. What materials were used during the servicing?
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Not sure.  Was done by a professional 
  • ChrisJ
    ChrisJ Member Posts: 15,671
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    Not sure.  Was done by a professional 

    Fair enough,
    Do you know roughly what they did? Piping, vents etc?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ratherbfishing
    ratherbfishing Member Posts: 32
    edited February 2023
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    Clean the pigtail and pressure control.
    Clean the probe/float type of low water cut off.
    Clean the glass gauge and valves.
    Clean the burner tubes.
    Inspect the flue passage ways in between the boiler sections.
    Perform a combustion analysis and make any adjustments if needed.
    Test the boiler water PH and add chemical, baking soda or like to get pH between 7 and 10
    Add rectorseal treatment 

    No vent work
  • neilc
    neilc Member Posts: 2,703
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    Clean the pigtail and pressure control.

    not sure if it's been asked,
    what's that pressure set to?
    and what's the gage telling you for high pressure when boiling?
    pictures?
    known to beat dead horses
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Pressure breaks right before 1.5 psi , cuts in at about 0.5. I installed a low pressure guage to track it.  Builds pressure slowly. 
  • ChrisJ
    ChrisJ Member Posts: 15,671
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    Pressure breaks right before 1.5 psi , cuts in at about 0.5. I installed a low pressure guage to track it.  Builds pressure slowly. 
    What does slowly mean?  30 minutes?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    30-40 minutes last I timed it.  
  • BobC
    BobC Member Posts: 5,477
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    Is the 30-40 minutes from a cold start? It's more helpful to know what the time is from a warm start, say 10 minutes after the boiler stops a steaming cycle.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Is a warm start any start after a full cycle when it's still hot to touch.  How would you define the interval post cycle?
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    Just curious,  I hear alot of "swooshing" when it's running and thy gauge water level does jump a bit (always done this). Could it be too much rectorseal?  The water in the guage isn't very pink at all though
  • neilc
    neilc Member Posts: 2,703
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    post a picture or 2 of the boiler, floor to ceiling, so we can see attached piping,
    and a close up on the controls, and sightglass,
    "Whooshing" and a bouncing water line, sounds like dirty water / wet steam,
    Do you have a skim port and knowledge to use it?
    known to beat dead horses
  • reggi
    reggi Member Posts: 511
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    Maybe there's a leak in the main that may not be as obvious as this... Was this replaced or taped ? After 4 months of heating the band-aid may need changing. 
     Photos please...
    You can "kick the can down the road" 
    only so far...
     

    One way to get familiar something you know nothing about is to ask a really smart person a really stupid question
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    @reggi taped. But doesn't seem to be leaking.  That's on the short line.  Theoretically, wouldn't a leak in the main cause that Main to heat faster as it's venting quickly?

    Will get some pics soon
  • reggi
    reggi Member Posts: 511
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    It's been 4 days since
      Huge difference.  The short main heats up much quicker now,  similar to previous.  It seems to have fixed it,

    is it still functioning correctly?

    One way to get familiar something you know nothing about is to ask a really smart person a really stupid question
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    @reggi for the time being!
  • reggi
    reggi Member Posts: 511
    edited February 2023
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    So the first response 2 weeks ago seems to of been correct , and one of the easiest 
    items to do..less than 10 -15 minutes..but because you didn't understand or listen to the explanations of WHY you kept looking for other causes until Finally your halfhearted attempt cleared it up... for now ? 
    Here's some more advice... if flushing the sight glass for a bit cleared up the issue expect it to return because you didn't get the oils off the top by draining down .. skimming would do that...  And you didn't get any sludge from the boiler's bottom because you didn't open any drain valves, you got what was suspended in the water from agitation of the boiler heating and circulation... not where it's coming from..
    Skimming and flush should be on your list to do to help eliminate a repeat
    My 2¢




    @Steamhead said:
    Dirty boiler water?
    ratherbfishing said:
     So maybe dirty water ( it is very dirty) but how would that change it?


    @ratherbfishing said:
    I decided to flush the boiler as recommended above. I was draining from bottom valve of sight glass and noticed it wasn't terribly dirty and running clear pretty quickly. So i stopped draining,
    One way to get familiar something you know nothing about is to ask a really smart person a really stupid question
  • ratherbfishing
    ratherbfishing Member Posts: 32
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    @reggi thanks for the insight. I actually do accept the suggestion it was dirty but I inquired more to learn a bit.  I find steam interesting but very frustrating as I bought a house with a system that wasn't installed "correctly".  From this forum, I got someone very skilled to service the boiler. I'll bring up skimming for next year. I don't think I have a skim port so likely beyond my skill/time set. As always, appreciate your insight.