Pressure drop

Discussion in 'Pumps and Tanks Well Forum & Blog' started by smithwd, Dec 23, 2009.

  1. smithwd

    smithwd New Member

    Messages:
    17
    Location:
    Marlborough, CT
    after my submersible pump pumps up to the set pressure of #60 it stops as it should but the pressure on the gauge drops immediately to #50. I
    ve tried this running water through the cycle and again shutting off the faucet as soon as it starts to pump....

    no air in the lines.

    xtrol bladder pressure is #29....................

    the check valve rattles during filling..(i was told this can happen)...is it possible the check valve is bleeding pressure until it gets to something it can handle??
  2. Gary Slusser

    Gary Slusser That's all folks!

    Either the check valve is leaking or the water line from the pump to the pressure gauge is leaking. Check valves usually don't rattle if they are good.
  3. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Is the pressure switch set 40/60 ? if so it should have 3 lbs of air in the tank.
  4. Bob999

    Bob999 In the Trades

    Messages:
    448
    Location:
    Pennsylvania
    Peter meant to say it should have 38 lbs of air in the tank if the pressure switch is set 40/60.
  5. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Fat fingers :(

    Thanks
  6. smithwd

    smithwd New Member

    Messages:
    17
    Location:
    Marlborough, CT
    it looks like the low end is around 38.........29 is still low but should not cause what i'm seeing..........

    i like the check valve idea....it does take a little longer to pump up to pressure..

    thanx for the help guys.....now I can talk to my plumber and impress him....on second thought he might charge me more....i'll play dumb.....

    have a merry
  7. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Try this. Let it pump up and shut off and then shut the breaker off to the pump and see how far it continues to drop, if at all. If it drops to zero, you probably have a bad check valve or a line leak. If it only drops the 10 lbs, try changing the gauge or just forget about it.
  8. Gary Slusser

    Gary Slusser That's all folks!

    If the pressure falls to like 40 and the pump comes on, it can't be the gauge...
  9. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    I should have said " and the pump comes on"
  10. smithwd

    smithwd New Member

    Messages:
    17
    Location:
    Marlborough, CT
    it does the pressure drop but still has enough pressure to prevent the low setting from kicking it on...I can draw water until the low switch kicks on...

    he just makes me nervous to watch the gauge go to 60 and then drop if the system is closed at that time the pressure i being lost somewhere..

    ....
  11. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    If....... you have all the faucets shut off and you are not drawing water and.... the pump does not come on for no reason then I would forget about it and enjoy your Christmas Turkey. It's probably a bad gauge
  12. Gary Slusser

    Gary Slusser That's all folks!

    I say it is a bad check valve or other leak and if he runs the pump at 40/60, then he needs to get 39-38 psi air pressure in the tank with no water in it.
  13. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Yea, it very well could be, but as long as the pump ain't cycling I don't think I would screw with it. He probably has a check at the tank inlet as well as the one on the pump.
  14. Gary Slusser

    Gary Slusser That's all folks!

    ummmm building up to 60 and then falling back to 50 right away, if the switch is set for 40/60, the pump is coming on at 40 and the gauge shows the decrease it can't be the gauge but, the the pump is cycling 2 times as often as it would with the other 10 psi in the tank. And cycling kills pump motors.

    Usually things that aren't working right don't get better, they get worse and it is easier and smarter to replace something now when he has water than doing it maybe the end of Jan. when he has no water and no choice.
  15. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Did he say the pump was cycling? I thought he said it drops from 60 to 50 and stays there.
  16. Gary Slusser

    Gary Slusser That's all folks!

    That's right, it holds at 50 until he uses water.
  17. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Does it come on as soon as the faucet is opened or does he have some draw down first? He didn't say
  18. smithwd

    smithwd New Member

    Messages:
    17
    Location:
    Marlborough, CT
    it draws down normally from 50....

    one thing I might throw out......I have a water treatment system for iron and salt etc........2 tanks involved.......I wonder if one of them might have a bladder type system or whatever that is taking the 10psi....I have a call into my water treatment person who also does wells, pumps etc to get some info..

    if i can open the valves I will try and isolate the treatment system..if not I'll wait for this guy

    hope everyone had a good safe xmas...........today is road icing...
  19. Gary Slusser

    Gary Slusser That's all folks!

    There is no bladder etc. in water treatment equipment that would use 10 psi when the pump shuts off.

    Plus, you can (and should) shut off the water past the pressure tank which should shut off the water to the equipment and the house. IF the 60 falls to 50 then, you have a bad check valve or a leak that is not leaking with less than 50 psi. And it is between the check valve and the shut off valve you closed just past the pressure tank.
  20. smithwd

    smithwd New Member

    Messages:
    17
    Location:
    Marlborough, CT
    Called in my water treatment system person (does wells also )...

    Problem is with the galvanized elbow on the bottom of the Extrol tank being somewhat restricted....tank is 10 years old.....
    we could overide the switch and build the pressure up to 60 to validate the findings.....

    will replace with plastic tank and stainless elbow........

    flutter in check valve is normal for some units.....

    P>S> he told me that a home inspector wouldn't have detected my problem as a problem.....makes me feel think twice about home reports..........

    thanx for all the help....
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