(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 7 of 7

Thread: bad pressure switch??

  1. #1
    HomeownerNotPlumber JBax's Avatar
    Join Date
    Feb 2013
    Location
    FL
    Posts
    1

    Default bad pressure switch??

    I am no well/pump expert but have changed a pressure switch a couple times on this unit since 1995. Lost water and replaced pressure switch Monday evening and this am when I got up and no water. An hour after I switched the power off, switched it on an the pump started running. Even though it is a 20-40 switch, the pump is running and the guage reads ~52 when it goes off. I tried adjusting the small nut to make it shut down sooner but that has no effect. When I turned the large nut counter cw the pump shut off. Later when water was used, it seemed pump would come on every time when normally this would not be required. At at some point, the pump would not go off and I shut power again. I checked the valve on top, drained tank and pressure is now~t 34. I am beginning to wonder if I bought a defective pressure switch. I have always gone to the same Bowen supply but this time although the switch looks the same it is not the SquareD brand I am familiar with, still have box from previous as I had drawn picture for hooking wires back up on it.

  2. #2
    Jack of all trades DonL's Avatar
    Join Date
    Mar 2011
    Location
    Houston, TX
    Posts
    3,661

    Default

    The small adj is normally the differential and the large one sets the pressure.

    You may have a loose connection to the switch, or dirty contacts.

    Could also have a restriction / debris on the pressure input to the switch, Your gauge could be reading off some also.

    SquareD brand is good.
    Theory only works perfect in a vacuum.

    Cyber Security Protection for Windows C:\ > WWW.WinForce.Net

  3. #3
    DIYer, not in the trades LLigetfa's Avatar
    Join Date
    Feb 2011
    Location
    NW Ontario, Canada
    Posts
    3,687

    Default

    The smaller of the two springs can be used to increase the cut-out and/or delta but cannot decrease the cut-out below what the big spring is set at. The big spring will raise/lower both the cut-in and cut-out at the same time, keeping the delta about the same.

    When you lower the cut-in, you must lower the precharge on the bladder as well. Keep in mind that neither your water pressure gauge nor your air pressure gauge are to be trusted. Either can be off. When setting the air precharge, your air pressure gauge needs to be calibrated to the water pressure gauge. When not at zero, the water pressure gauge reading should be compared to the air pressure. Both should read identically. If they do not, at least one of them is lying.

  4. #4
    DIY Senior Member craigpump's Avatar
    Join Date
    Apr 2012
    Location
    ct
    Posts
    717

    Default

    The best way to set tank precharge is to drain all the water out and then check & set the air charge to 2 psi below cut in pressure. I don't trust el cheapo tire pressure gauges so I use a a tire inflation chuck with a glycerin filled gauge to check the tank pressure. Throw the cheap dry gauge out and install a stainless steel glycerin filled gauge.

  5. #5
    Moderator valveman's Avatar
    Join Date
    Mar 2006
    Location
    Lubbock, Texas
    Posts
    4,175

    Default

    Sounds more like the nipple the pressure switch is attached to is clogged up than a bad switch.

  6. #6
    DIYer, not in the trades LLigetfa's Avatar
    Join Date
    Feb 2011
    Location
    NW Ontario, Canada
    Posts
    3,687

    Default

    Quote Originally Posted by JBax View Post
    I checked the valve on top, drained tank and pressure is now~t 34.
    This statement is not clear to me. What did you actually do by checking the valve on top and why before draining the tank? Is it the air pressure on the bladder after draining that is 34 PSI or what? A 20/40 switch should have 18 PSI precharge but after screwing with both adjustments, it's impossible to know now.

    Before you fiddled with the nuts, I would concur with valveman that you have a blockage in the nipple but now it might be more than that.

  7. #7
    Jack of all trades DonL's Avatar
    Join Date
    Mar 2011
    Location
    Houston, TX
    Posts
    3,661

    Default

    The old switch must have been adjusted for around 35/55.
    Theory only works perfect in a vacuum.

    Cyber Security Protection for Windows C:\ > WWW.WinForce.Net

Similar Threads

  1. Low pressure, pump stays on - tank, pressure switch? Replace all?
    By applebach in forum Pumps and Tanks Well Forum & Blog
    Replies: 10
    Last Post: 04-17-2011, 04:51 AM
  2. Super High pressure, but pressure switch appears to work properly
    By yergnov in forum Pumps and Tanks Well Forum & Blog
    Replies: 8
    Last Post: 03-03-2009, 05:14 AM
  3. Flussmatic Marina vs Pressure tank and Pressure switch
    By Eddievan in forum Irrigation / Sprinkler Forum
    Replies: 3
    Last Post: 01-20-2009, 05:35 AM
  4. Replies: 1
    Last Post: 05-14-2008, 10:13 AM
  5. 2 Houses, 2 Pressure Tanks, 1 pump, 1 controller, 1 pressure switch pro help needed!
    By betaman in forum Pumps and Tanks Well Forum & Blog
    Replies: 12
    Last Post: 05-05-2008, 05:07 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •