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How do i tell if my gauge is bad?

Hi everyone, I'm back for some more help after more than a year. I've got my one pipe system running great, very quiet and even.

I was just down in the basement and noticed that the gauge on the boiler (oil Peerless ECT-03) is reading around 17psi. This is the gauge on the round cover plate. I'm worried because there's a sticker on the boiler that says "mawp steam 15psi". Now the cut in is set at 2psi and the diff is between 1 and 2, so is my gauge bad? Does that guage give pressure in the system or just the boiler (wait, that should be the same, right?)? It looks easy enough to replace, but is there a way to be sure it's bad before I replace it?
Thanks in advance.


  • Big Ed
    Big Ed Member Posts: 1,117
    Pop Safety

    The pop safety should have released at 15# . I would try a second gauge . First guess, it's off.
  • new gauge

    Make sure you have a pigtail installed to protect the new gauge or it may not last long.
  • tom collins
    tom collins Member Posts: 5

    How do i know if there's a pigtail?
  • Eli
    Eli Member Posts: 42

    The pigtail is the loop of tubing to which the gauge should be mounted. The loop captures water and acts as a buffer between the gauge and the system. Also, the pigtail can get clogged up so take the whole thing apart and make sure the pigtail is clear and clean (soft wire, like the bare conductor from 14 gage romex makes a good cleaning tool). Try pressurizing the gauge (gently) by blowing on it, see if the needle's stuck.
  • Heres a recent install

    I used to have the gauge go directly into the ECT boilers , but found out they do not last long in direct contact with steam . We install the gauge after the pigtail on every job now , and they hold up much longer .
  • GW
    GW Member Posts: 4,676
    the old fassioined way

    you could remove the gage, get about 10 feet of clear vinyl tubing, assemble some crude yardstick like gage, fill it with water, and see the water level climb, measure the difference, 1 psi is 2.3 feet.

    better make it 14 feet...and get your wife to help, you'll need more than the standard issue two arms.


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  • tom collins
    tom collins Member Posts: 5

    thanks for the picture! that makes sense. Is is ok if the pigtail just goes to the gauge? my pressuretrol is already mounted above the thing with the valve where i periodically dump some water (low water cut-off?). By the way, the pressuretrol is mounted on a pigtail. Another question: I notice in your picure there's a tee coming out of the cover plate, could I just do a 90 out of the plate to a pigtail, and then a 90 to the gauge?
    Thanks again, it's not that I'm too cheap to have a pro do this, I'm a teacher and having enough trouble just paying the oil bills this winter!
  • scrook_2
    scrook_2 Member Posts: 610

    you could use a 270° (one end prerpendicular to the other) pigtail instead of a 360° (both ends parallel) (or vice virsa) and a bottom connection gauge instead of a rear connection gauge.

    Pressuretrol on one pigtail (on your float type low water cut off or LWCO) and the gauge on another is fine, but check'm both to be sure they are not clogged, and add a little water to them when you put them back together so the p-trol and/or gauge doesn't see steam the first few cycles (the pigtail will fill with condensed water after a little while but better to fill it beforehand.
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