Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

grundfos well pumps

Steve Ebels_3
Steve Ebels_3 Member Posts: 1,290
The pump is able to deliver more water than the well can provide and "sucks" the casing dry.

On another note, a well that's 10 feet deep is hardly a well. More like a deep mud puddle. You need to go through a clay or other dense strata in order to protect yourself from harmful substances that are present in surface water. Drill a new one, it's not worth contaminating yourself with chemicals or getting a parasite infestation from surface water. JMHO


  • grindog
    grindog Member Posts: 121
    pump wont keep its prime

    Today i installed a grundfos mq series well pump. The well is 10 feet deep and waterlevel is less than two feet from the bottom, the original 1" suction line is under the water.
    I primed the pump and tuned it on. The pump is operating two silcocks and when i open them i get no preasure just a trickle. After i shut the silcock off the pump shuts off because it has lost its prime. There is a check valve installed on the suction side inlet and its installed properly because tank will hold preasure. I blew the lines out with my compressor and there is no blockage.
    What do you think is wrong with the pump? Not enough water in the well, or is the pump bad, any info would help
  • jeff_51
    jeff_51 Member Posts: 545
    Not familiar with that particular pump but

    what is the flow rate of the well vs the pumping capacity of the pump? You may well be pulling out all the water from the well and if the recovery is slow you suck air
  • Michal
    Michal Member Posts: 213
    Like Jeff said

    The well is 10 feet deep and waterlevel is less than two feet from the bottom, the original 1" suction line is under the water. you very well might be sucking the well dry?? what are the characteristics of the new pump versus the old one. Also is there a check valve installed to keep prime? And are your connections tight, that will be a big problem if they are not???? You also need to know what gpm that well is rated at????
  • grindog
    grindog Member Posts: 121
    its old

    The original pump was a sears roebuck piston style that had not been operational for years, dont know the gpm or horse power at this moment but the pump is piped correct and i have the flow check installed correctly.
    I think the well can not keep up with the pump we have had no real rain lately and when i looked at the job 3 weeks ago there was a lot more water in the well it has dropped about five feet in three weeks.
  • Shawn Chong
    Shawn Chong Member Posts: 1
    MQ pump

    Before I attempt to answer these questions, here are several questions I have pertaining to this issue.
    1. You mentioned that "After i shut the silcock off the pump shuts off because it has lost its prime", did a red light come on in the alarm mode on the control panel?
    2. Is there an additional foot valve down the pipe 10 feet down in the well?
    Here is a brief description as to how the MQ pump works.

    The MQ pump will turn itself on based on two conditions. One, it will turn on when there is a cummulative flow of 0.3gpm. Second, it will also come on when the pressure is below 28psi. This is accomplished via the pressure switch and flow switch. The only way the MQ will shut itself off under normal conditions (without red light on the control panel) is if the flow rate is 0 gpm. If you have a condition such as dry running, overtemperature, overload or blockage of the pump, the red alarm light comes on and it stops the pump.

    Hence, in order for you to verify that the pump did shut off based on a dry well, make sure that the alram light was on red. If not, you might want to redrain the pump (in case you have an air pocket) and make sure the tank pressure is set between 22psi to 25psi (can be easily checked with tire gauge). Let me know if you have questions. I can be reached at 913.227.3471.

    Have a great day.

    Shawn Chong
    Grundfos Pumps Corporation USA
  • Michal
    Michal Member Posts: 213

This discussion has been closed.