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What Causes High Pressure on Steam Boiler

nycpa
nycpa Member Posts: 108
Hi, i have a Weil Mclain EG45 Steam boiler. Recently, I had the pigtail which was completely clogged cleaned out and I found out the honeywell pressuretrol doesn't work. I am replacing it this weekend and replacing the main vent with two gorton 2's. Have less than 30ft of main with 2 inch pipe. While the boiler was running, i noticed the 0 to 30 gauge PSI reader has hovering around 8 to 9. I turned off my boiler right after. What's causing the pressure to be so high and how can I fix this? Thanks

Comments

  • Dave0176
    Dave0176 Member Posts: 1,176
    First has anyone done an EDR (load calculation of your radiators) to see if your boiler is oversized?? Second the pressuretrol controls boiler pressure, if yours isn't working I would not be running the boiler until it's replaced.
    DL Mechanical LLC Heating, Cooling and Plumbing 732-266-5386
    NJ Master HVACR Lic# 4630
    Specializing in Steam Heating, Serving the residents of New Jersey
    https://heatinghelp.com/find-a-contractor/detail/dl-mechanical-llc

    https://m.facebook.com/DL-Mechanical-LLC-315309995326627/?ref=content_filter

    I cannot force people to spend money, I can only suggest how to spend it wisely.......
  • Dave0176
    Dave0176 Member Posts: 1,176
    As far as the pigtail getting clogged, your boiler may need to be cleaned or even skimmed out.
    DL Mechanical LLC Heating, Cooling and Plumbing 732-266-5386
    NJ Master HVACR Lic# 4630
    Specializing in Steam Heating, Serving the residents of New Jersey
    https://heatinghelp.com/find-a-contractor/detail/dl-mechanical-llc

    https://m.facebook.com/DL-Mechanical-LLC-315309995326627/?ref=content_filter

    I cannot force people to spend money, I can only suggest how to spend it wisely.......
  • nycpa
    nycpa Member Posts: 108
    Boiler was put in in 1984, seemed to work fine until recently, how would I skim it out?
  • BobC
    BobC Member Posts: 5,379
    edited October 2014
    What was the pressure before you had the pigtail fixed? Do the air vents seem to be making more noise? With 8 or 9 psi they should be complaining loudly and could be damaged by the high pressure. Is the gauge on the end of what was a clogged pigtail? Do you know that gauge is working correctly?

    If the pressuretrol isn't working the boiler is capable of making pressure until the 15 pound pressure relief valve pops IF the boiler EDR is much larger than the radiator total EDR. If you are in the cellar when that happens you will remember it for a long time!

    Your gauge could be bad but I would keep the boiler off until you get a working pressuretrol to be safe.

    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
  • nycpa
    nycpa Member Posts: 108
    Before fixing the pigtails, I never seen the gauge ever move, now I see it going up slowly to 8 psi, the air vents aren't making that much noise other than the occasional hiss, how do I test to see if the gauge works, the gauge was not the end of the clogged pig tail
  • Fred
    Fred Member Posts: 8,540
    Did anything else change on the boiler or system? How long did the boiler run before the pressure got that high? Did you jack the thermostat way up and let the boiler run for an extended period of time? With a defective or out of adjustment Pressuretrol, the pressure will build if the boiler runs for extended periods. I'd get the pressuretrol fixed/replaced, set the cut-in at .5psi and the differential at 1psi and I'd put a 0 to 3 psi gauge on that same pigtail so you can see what is actually happening. Your 0-30psi gauge may be defective for all we know. If the boiler worked since 1984, without pressure problems, I wouldn't be to concerned about EDR.
    MilanD
  • BobC
    BobC Member Posts: 5,379
    You would have to put a known good gauge on the boiler and see what it reads. If the air vents are not making a lot of noise I suspect the gauge might be bad BUT I would get the pressuretrol working before running the boiler.

    Out of curiosity what is the pressuretrol set to work at and why do you think it is bad? If you remove the pressuretrol and turn it upside down, look into the brass fitting and make sure the little hole at the bottom isn't blocked. If that pigtail was blocked it's possible the pressuretrol is blocked also.

    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
  • Dave0176
    Dave0176 Member Posts: 1,176
    Fred said:

    Did anything else change on the boiler or system? How long did the boiler run before the pressure got that high? Did you jack the thermostat way up and let the boiler run for an extended period of time? With a defective or out of adjustment Pressuretrol, the pressure will build if the boiler runs for extended periods. I'd get the pressuretrol fixed/replaced, set the cut-in at .5psi and the differential at 1psi and I'd put a 0 to 3 psi gauge on that same pigtail so you can see what is actually happening. Your 0-30psi gauge may be defective for all we know. If the boiler worked since 1984, without pressure problems, I wouldn't be to concerned about EDR.

    Yes a lot more has been explained now.
    DL Mechanical LLC Heating, Cooling and Plumbing 732-266-5386
    NJ Master HVACR Lic# 4630
    Specializing in Steam Heating, Serving the residents of New Jersey
    https://heatinghelp.com/find-a-contractor/detail/dl-mechanical-llc

    https://m.facebook.com/DL-Mechanical-LLC-315309995326627/?ref=content_filter

    I cannot force people to spend money, I can only suggest how to spend it wisely.......
  • nycpa
    nycpa Member Posts: 108
    The pressure from was set at 1differential and 2.5, it did stay on for a while before reaching the high psi, plumber said the spring was bad on it, wouldn't reset
  • williambarbjr
    williambarbjr Member Posts: 1
    I have a Columbia steam boiler which has the following problems - start last year with overfilling & banging - replaced the LWCO and feed, did not help. Then went to every radiator and replaced every steam vent (only cause a couple of vents to drip. Noticed that the gauge read over 3 1/2 psi - pressure trol was set at .5 with diff of 1, replaced with new one (pigtail clear), went bad today because drip at one of steam vents, pressure up to 5 psi. Boiler is located in retirement home with many rooms ( all of which are extremely hot so manager has all but turned radiators off), the thermostat is located in a large open room on first floor (always calling for heat). Basically replaced all controls. What is causing the psi to be so much than pressure trol (why does it shut down boiler). The boiler has been operating for years under these conditions. I've already spoke to manager the install another heat source in room with T-stat. I'm at a lose as to why these problems have just started and what is the remedy.
  • JUGHNE
    JUGHNE Member Posts: 10,278
    Your steam main vents may have been over pressurized if dripping water onto the pressure control??
    Pictures of controls and main vents would help.
  • A boiler is called a high-pressure boiler when it operates with a steam pressure above 80 bars. The high-pressure boilers are widely used for power generation in thermal power plants.
    In a high-pressure boiler, if the feed-water pressure increases, the saturation temperature of water rises and the latent heat of vaporization decreases. The feed water can be heated to saturation of temperature in the economizer with the help of waste heat. Recovery from the exhaust gases is escaping to the chimney. Then the boiler supplies only latent heat of vaporization and superheat. Thus, a boiler operation at high pressure will require less heat addition for steam generation.
  • Sailah
    Sailah Member Posts: 826
    In our steam heat world we consider over 75 PSIG high pressure. Power plant stuff is an entire other realm.
    Peter Owens
    SteamIQ
  • ChrisJ
    ChrisJ Member Posts: 13,863
    Sailah said:

    In our steam heat world we consider over 75 PSIG high pressure. Power plant stuff is an entire other realm.

    80 bar is 1160 PSI.
    That's scary.
    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
  • ratio
    ratio Member Posts: 3,331
    If you think that's scary, Google "super critical steam".
  • Abracadabra
    Abracadabra Member Posts: 1,948

    A boiler is called a high-pressure boiler when it operates with a steam pressure above 80 bars. The high-pressure boilers are widely used for power generation in thermal power plants.
    In a high-pressure boiler, if the feed-water pressure increases, the saturation temperature of water rises and the latent heat of vaporization decreases. The feed water can be heated to saturation of temperature in the economizer with the help of waste heat. Recovery from the exhaust gases is escaping to the chimney. Then the boiler supplies only latent heat of vaporization and superheat. Thus, a boiler operation at high pressure will require less heat addition for steam generation.

    Obviously spam

    RomanGK_26986764589
  • Paul48
    Paul48 Member Posts: 4,469
    My father use to talk about 10000 psi off a reactor.
  • BobC
    BobC Member Posts: 5,379
    And that is why a pressurized water reactor is nothing but a bomb looking for somewhere to explode. Much safer to use a liquid metal fueled reactor that operates at room pressure - no boom.

    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
  • ColinFarquhar
    ColinFarquhar Member Posts: 16
    To keep things a little more in line... here in North America a heating/low pressure boiler is 15psi or less, over 15PSI is considered high pressure/power boiler territory. Conveniently lines up with ASME for Power Boilers or Heating Boilers (Section i or Section IV).
  • in my sisters building we had A new Super come along,My sister Lives On The fifth Floor,she s had These Holes In her ceiling,so The super Lights Up The boiler,it s been Holy Hell Ever since,Yesterday,I Went Down In The boiler room,Looked At Honeywell Pressuretrol Gauge,It s At 78,Now theres a New super
  • Ying
    Ying Member Posts: 58
    nycpa said:

    Hi, i have a Weil Mclain EG45 Steam boiler. Recently, I had the pigtail which was completely clogged cleaned out and I found out the honeywell pressuretrol doesn't work. I am replacing it this weekend and replacing the main vent with two gorton 2's. Have less than 30ft of main with 2 inch pipe. While the boiler was running, i noticed the 0 to 30 gauge PSI reader has hovering around 8 to 9. I turned off my boiler right after. What's causing the pressure to be so high and how can I fix this? Thanks

    @nycpa Will you mind updating what happened after you switch out the pressuretrol?

    I'm having the same problem, replaced the clogged pigtail last week and pressure still climbing to like 10. Want to make sure that changing the pressuretrol will solve the problem or maybe it is just the gauge reading wrong.
  • Jamie Hall
    Jamie Hall Member Posts: 20,416
    @Ying -- it would be better to start a new thread... that said, there are a number of possibilities, ranging from a faulty pressuretrol (not that likely) to a miswired pressuretrol to a clog where the pigtail goes into the boiler to ...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Ying
    Ying Member Posts: 58
    edited January 2019
    @Jamie Hall lol, I did. Just looking to do more research on the topic.

    I believe you responded on that thread a few days ago.

    Was looking to do what you suggested on a low pressure psi gauge and put it on the pigtail, but none of the hardware store around me seems to stock them. Are you able to post a link to an online store that I can buy from or maybe to name of the part so I can search for it on supply house or amazon.

    Also you mention throwing an elbow on it, does the low psi gauge need to be up right or can it be installed vertically.

    As for the wires in the pressuretrol (Honeywell substantive 1PSI to 8PSI), there are only 2 wires. Red wire connected to the R screw on top and grey wire on B screw on bottom). Is this not correct?