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creeping up boiler pressure

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carl3633
carl3633 Member Posts: 2
in THE MAIN WALL
my boiler pressure keeps creeping up. I have replaced the expansion tank (air charge verified correct), the auto fill valve (set to fill at 15 psi), air vent, and pressure relief valve. There is no hot water coil. I have a boiler mate and I'm wondering if I can test the the coil in it to see if it might be cracked and letting my well water system to bleed pressure into the boiler.

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  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,577
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    First shut off the automatic feed to the boiler. The prv may be leaking by. Try that first. If the pressure continues to rise with the water shut off you can disconnect the boiler mate coil plug 1 connection and test that. Or install two valves between the boiler mate and the boiler is probably a better idea
    GordyZman
  • j a_2
    j a_2 Member Posts: 1,801
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    Whoops, fill valve thing again...Leave it off at all times except for initial filling and stabilization, was my policy.....If fill valve is truly off and holding ,your issue is most likely the coil in the water tank....Careful how you describe it when looking for any manufacture warranty....Some warrant the tank for extended periods, but the coil is not....tricky tricky manufactures
  • carl3633
    carl3633 Member Posts: 2
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    thanks for the replies. confirms my thoughts on the boiler mate. will up date post when fixed
    Mike
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,022
    edited July 2017
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    This is a common problem and one that has had me perplexed for years. Check the x-tank, replace the fill valve or somehow test the HX coil in the indirect. I can't tell you how many times everything has checked out fine, but the pressure continues to go up.
    The latest one to add to the list is a bad Spirovent. For some reason, something in the Spirovent made the pressure go up.

    There's magic in hydronics, but sometimes it's bad magic, no?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • j a_2
    j a_2 Member Posts: 1,801
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    Alan (California Radiant) Forbes said:

    This is a common problem and one that has had me perplexed for years. Check the x-tank, replace the fill valve or somehow test the HX coil in the indirect. I can't tell you how many times everything has checked out fine, but the pressure continues to go up.
    The latest one to add to the list is a bad Spirovent. For some reason, something in the Spirovent made the pressure go up.

    There's magic in hydronics, but sometimes it bad magic, no?

    I just have to know, how does a spirovent cause the pressure to go up...
    Jean-David Beyer
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,022
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    See here:

    https://forum.heatinghelp.com/discussion/156148/x-tank-blind#latest
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • j a_2
    j a_2 Member Posts: 1,801
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    Alan (California Radiant) Forbes said:

    See here:

    https://forum.heatinghelp.com/discussion/156148/x-tank-blind#latest

    Read thru the posts, but still confused how a spiro vent can increase pressure...
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,022
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    The Spirovent's x-tank connection gets clogged. Seemingly (rarely) prone to Spirovents....
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • j a_2
    j a_2 Member Posts: 1,801
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    So it's not really really the spirovent causing the pressure to rise...because it's pretty much impossible
  • zmcgarvey
    zmcgarvey Member Posts: 20
    edited August 2017
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    I believe he means that the bottom port (1/2 npt tapping) on the spirovent got clogged with junk, thus not allowing the x-tank connected to it to do its job. However, this should cause the pressure to go up when hot (no place for the increased volume of water to go other than to press outward), then return to normal when cold. So something isn't being described accurately here.
  • MilanD
    MilanD Member Posts: 1,160
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    > @carl3633 said:
    > thanks for the replies. confirms my thoughts on the boiler mate. will up date post when fixed

    So what was it @carl3633?
  • j a_2
    j a_2 Member Posts: 1,801
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    zmcgarvey said:

    I believe he means that the bottom port (1/2 npt tapping) on the spirovent got clogged with junk, thus not allowing the x-tank connected to it to do its job. However, this should cause the pressure to go up when hot (no place for the increased volume of water to go other than to press outward), then return to normal when cold. So something isn't being described accurately here.

    I agree totally if that's what's happening, but it was the wording that could be misleading. Spirovent causes pressure increase?
  • Big Ed_4
    Big Ed_4 Member Posts: 2,799
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    Give me that cheap cast iron air scoop and float bleeder any time ..

    There was an error rendering this rich post.

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