Float Switch Failure

Discussion in 'Pumps and Tanks Well Forum & Blog' started by Dungmin, Dec 12, 2008.

  1. Dungmin

    Dungmin New Member

    Messages:
    16
    Fourteen months after successfully installing a float switch in my cistern to control the water level fed by a well pump (credit due to members of this forum who patiently saw me through the exercise), the switch evidently failed me last night as I awoke to an inch of water in my finished basement. I checked the position of the float switch and found it perfectly upright and improperly completing the closed circuit.

    I acquired this float switch from McMaster-Carr (p/n 51445K91), rated at 15 amps@120V, which is controlling a 24V relay. Can anyone recommend a more reliable switch or tell me if this is an uncommon (I would hope) failure? I'm considering installing two in series (mounting the second at a higher level) as a fail-safe measure, anything to prevent another such disaster.

    TIA for any advice!
  2. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    You should have a back up switch & pump with an alarm system...all switches & pumps fail it is just a matter of when...

    The problem with the back up switch is you won't know when the first one fails and then the second will eventually fail also so an alarm along with a back up switch & pump is what I would recommend.
  3. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    Cass is right. I sell a float switch just like yours and it probably wouldn't be any better than the one you already have.

    bob...
  4. thassler

    thassler New Member

    Messages:
    106
    Location:
    Tennessee
    I run three float switches on mine:

    1. Primary
    2. Alarm
    3. Backup

    That way the alarm sounds when the primary float fails, the Backup float kicks in and I know to replace the primary float.
  5. Dungmin

    Dungmin New Member

    Messages:
    16
    Thank you much gentlemen. As consent is unanimous, I've obviously got some upgrading to do.

    Quick question- is there an alarm switch you could point me to? I could improvise, but if there's an easier way I'm all for easy.

    Thanks again!
  6. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    3 switches and an alarm is good but that is only good if the switch fails...if the pump fails the back up switch and alarm makes no difference and the basement will flood...yes the alarm will sound but the basement will flood until you replace the pump and if your not home ...well...
  7. thassler

    thassler New Member

    Messages:
    106
    Location:
    Tennessee
    I think in Dungmin's situation (as in mine) if the pump quits, the water stops so no worries.
  8. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    NO...there is no way to stop ground water from filling a sump pump pit...unless it goes somewhere else...and that is what the pump is doing until it stops, it is sending it somewhere else...that is why your basement flooded in the first place....the pump stopped running, the pit filled, and the basement flooded...all the alarms in the world will not stop the pit from filling should the pump stop because of mechanical failure OR if you lose power...that is why battery back ups have batterys...Unless you install an alarmed battery back up, and I recommend the Zoeller Aquanott, it will just be a matter of time before you are in the same boat with a flooded basement.

    If your basement is unfinished then it is just and inconvenience...I have seen finished basements fill to almost the basement window level...
    Last edited: Dec 15, 2008
  9. thassler

    thassler New Member

    Messages:
    106
    Location:
    Tennessee
    I misunderstood Dungmin's situation then. In my case, I'm simply filling a cistern (outside holding tank) with water from a well. If the pump quits (well pump) - so does the water. Sounded like Dungmin was doing something similar only that his cistern was indoors. Cass, you are of course correct if he's talking about pumping water out of a basement sump.
    Last edited: Dec 15, 2008
  10. W.O.P Jeff

    W.O.P Jeff Junior Member

    Messages:
    12
    Location:
    Ottawa, Ontario
    You should see if you can find a Mercury float switch. They tend to last longer.
    Harder to find though depending where you are I am sure.

    Check out SJElectric
  11. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    I didn't notice that it was a cistern he was talking about...thought it was a sump...
  12. Dungmin

    Dungmin New Member

    Messages:
    16
    Gentlemen,

    Sorry to be in absentia for the later responses, but to verify- this is a float switch in a cistern. I've got our well pump pumping into a cistern (the well is a "dry hole" with the submersible pump protected by a Pumptec). The float switch controls the well pump with a separate pump in the basement drawing from the cistern. When I moved the well supply from going to the house to the cistern I ran polypipe along with the float switch wiring through 1¾" pvc through the basement and cistern walls. I didn't seal the ends of the pvc pipe (permitting air displacement venting in a tightly sealed cistern) and thereby created a perfect drain for an overflowing cistern, right into a finished basement. Mighty dumb, I know, along with trusting a single switch. My occupation is in the field of the electro-mechanical, and I was surprised that such a switch would fail after only fourteen months. This served as yet another reminder of both the expense and frustration that comes with assuming.

    My thanks again to all that contributed to my query.
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