35+ PSI boiler pressure. Have gone through the usual checks.

Discussion in 'Boiler Forum' started by mdgolfguy, May 29, 2013.

  1. mdgolfguy

    mdgolfguy New Member

    Messages:
    6
    Location:
    MD
    Hey Guys,

    I have a Burnham boiler with a Weil McClain indirect WH tank attached to it. I've noticed recently that water has been leaking from the PRV of the boiler and have seen PSI at around 35 at the high point. I've gone through the usual steps:
    1) I turned of the boiler and let the pressure hit 0. I read the expansion tank pressure and it was good, at around 12.
    2) I reduced the pressure to around 10 and shut off the cold water main to the auto feed valve. Pressure slowly rose over the next few hours
    3) I reduced the pressure to around 10 and shut off the cold water main to the indirect tank. Pressure slowly rose over the next few hours.
    4) Aquastat is set at 183. I have though seen it reach 220.

    Any idea what is wrong? Did I properly isolate the indirect tank and is my conclusion on that point valid?

    Thanks,

    Russ
  2. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    You may have two problems. It could be a bad auto feed. I realize your turning of the valve for the feed should eliminate the pressure from rising but the valve may not be holding.

    John
  3. mdgolfguy

    mdgolfguy New Member

    Messages:
    6
    Location:
    MD
    my set up is like this: cold water main, shut off valve, backflow preventer, auto feed, shut off valve, expansion tank. If both shut off valves are closed wouldn't that rule a faulty shut off valve out?
  4. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    If you're turning a valve off between the boiler and the expansion boiler pressure will rise when the water is heated. You cannot isolate the expansion tank from the boiler.

    John
  5. Dana

    Dana In the trades

    Messages:
    3,027
    Location:
    01609
    If the expansion tank is undersized it can still hit high pressures when the system is up to temperature. What happens to the pressure when you turn off the boiler-fill valves and the cold feed to the indirect?

    You may still have pressure on the indirect from mixer valves elsewhere on the system- open a hot water tap somewhere on the system after turning off it's cold feed, just to rule that out.
  6. mdgolfguy

    mdgolfguy New Member

    Messages:
    6
    Location:
    MD
    The valve is before the expansion tank

    DSCN0840 - Copy.JPG
  7. mdgolfguy

    mdgolfguy New Member

    Messages:
    6
    Location:
    MD
    Expansion tank was fine for a few years.

    When the auto feed valve and and the cold feed to the indirect are both closed, the pressure still rises.
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,317
    Location:
    New England
    Some things like shower valves and many single handle faucets can allow backflow, and bypass the water feed to the indirect by feeding into the hot water outlet. So, you may have to turn the water to the house off if you don't have a valve on the outlet of the indirect.
  9. mdgolfguy

    mdgolfguy New Member

    Messages:
    6
    Location:
    MD
    I have a valve on the hot water line that feeds out of the indirect.
  10. mdgolfguy

    mdgolfguy New Member

    Messages:
    6
    Location:
    MD
    Also, I did flush my water heater fairly recently. Not sure if that means anything.
  11. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,311
    Location:
    Maine
    With the auto feed off are only two things it can be. The expansion tank is bad or there's a leak in the indirect coil.

    Shut off the water feed to the indirect and the auto feed to the boiler. Drop the pressure in the indirect tank to below 12 lbs. fire up the boiler. If the pressure doesn't climb, the indirect coil has a hole in it.

    If the pressure still climbs, your expansion tank is bad.
    Last edited: May 29, 2013
  12. bluefleetwood

    bluefleetwood New Member

    Messages:
    11
    Location:
    Setauket, NY
    Can I assume you mean, "Firing Up The Boiler" by turning the stat on the Indirect Up to call for Hot Water?
    Sounds like I should be performing this test as well.
    http://www.terrylove.com/forums/sho...-Boiler-Pressure-to-increase-pop-of-t-P/page2
  13. lkgproducts@gmail.com

    lkgproducts@gmail.com In the Trades

    Messages:
    3
    Location:
    cleveland ohio
    You can test that boiler with the all purpose pressure tester
  14. lkgproducts@gmail.com

    lkgproducts@gmail.com In the Trades

    Messages:
    3
    Location:
    cleveland ohio
    have you ever heard of the appt testers and kits?
  15. bluefleetwood

    bluefleetwood New Member

    Messages:
    11
    Location:
    Setauket, NY
    No I haven't, Where do I acquire one?
  16. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,311
    Location:
    Maine
    Fire the boiler up. It makes no difference what calls the burner. There is no tester made that will pinpoint the leak. The boiler already has a pressure gauge on it.
  17. bluefleetwood

    bluefleetwood New Member

    Messages:
    11
    Location:
    Setauket, NY
    Thanks Tom,
    PRV Still leaking, Pressure in boiler still not exceeding 28 PSI.
  18. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,311
    Location:
    Maine
    Replace the indirect. The pressure won't go much higher in the boiler because you have a very small leak in the indirect coil and the relief valve is leaking it off.
  19. bluefleetwood

    bluefleetwood New Member

    Messages:
    11
    Location:
    Setauket, NY
    Thanks Guys,
    New Indirect Installed. Smaller Unit with same volume, Much more efficient. Boiler pressure remaining at 12PSI. Now to completely empty old one to get to supplier for refund.
    Again thank you all for your help!
  20. lkgproducts@gmail.com

    lkgproducts@gmail.com In the Trades

    Messages:
    3
    Location:
    cleveland ohio
    HAVE YOU CHECK OUT www.appttestersllc.com or amazon.com just punch in appt testers. or ask @ your supply house or contact me toll free 855 808 lkg1(5541 and i will set you up.

    i am a plumber by trade and inventor of the ALL PURPOSE PRESSURE TESTERS & KITS LOUIS GIORDANO
Similar Threads: boiler pressure
Forum Title Date
Boiler Forum Boiler pressure reducing valve, pressure relief valve or both Dec 4, 2014
Boiler Forum How to manually increase boiler pressure? Dec 2, 2014
Boiler Forum Boiler Pressure increases when heats up. Nov 21, 2014
Boiler Forum Leaking Watts 1156F boiler pressure reducing valve Nov 20, 2014
Boiler Forum Ongoing Intermittent Boiler Over Pressure Issue Aug 14, 2014

Share This Page