Rapid Cycle Well Pump

Discussion in 'Pumps and Tanks Well Forum & Blog' started by warrens, May 19, 2013.

  1. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Hi

    (NB SUBJECT SHOULD BE RAPID CYCLE NOT RECYCLE!)

    I have had constant problems with my well pump (400 feet deep) running dry and then either frying the pump or heating the pipe up so much that it bursts and my well guy comes and pulls it out to replace the piece of pipe.

    the main reason I believe this was happening (apart from the fact that I have a very low producing well which means I have to manage water very carefully) was because my wires were the wrong gauge so the pumptech was never shutting the pump off in time to save this.

    I believe I have mainly solved this problem since purchasing a cycle sensor valve through suggestions on this site.

    That has worked well telling me when the well is dry and shutting off the valve, however I am now having a RAPID CYCLING problem. I have water in the well and if I turn off the RAPID CYCLING reset then the pump works fine. Otherwise it seems to go into recycle when it reaches the cut off pressure.

    I have 2 thoughts

    1. there is a hole in the pipe as before, however it is still able to pump water up
    2. the pressurized water tank has a leak, however it appears to be working fine and has good pressure

    any thoughts suggestions welcome


    I can bypass the RAPID CYCLE cut off but dont want to fry my pump again

    thanks Warren
    Last edited: May 19, 2013
  2. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,126
    Location:
    NW Ontario, Canada
    Isolate the tank outlet and see if you are losing pressure when the pump shuts off, assuming you don't have a topside checkvalve to mask it.

    Are you sure it is recycle and not rapid cycle?

    Quoting from http://www.cyclestopvalves.com/prod_sensor_geninfo.html
  3. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Thanks LLigetfa

    Yes you are correct I should have said rapid cycle. I will have a look re losing pressure when the pump shuts off and get back to you
  4. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Hi

    I checked for losing pressure and it seems ok-it stays at a constant pressure
  5. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,126
    Location:
    NW Ontario, Canada
    Then do a drawdown test to see if the tank is waterlogged.
  6. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Thanks, can you just guide me as to what exactly in simple terms I have to do to do the drawdown test to evaluate this

    thanks
  7. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,126
    Location:
    NW Ontario, Canada
    When the pump reaches the shutoff pressure, draw off water from the tank into a pail and measure how many gallons you can draw down until the pump kicks back on. That will tell you how much drawdown you have. If you don't get as much drawdown as you should, then there is probably a leak in the bladder.

    For example, a 40 gallon tank should give you 12 gallons of drawdown with a 30/50 pressure setting.
  8. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Thanks again LLigetfa,

    I have done the drawdown test and it seems fine I get about 8 gallons on a 20 gallon tank at 20/40 pressure setting. I also tested the pressure of the tank empty and at the cut off and cut in and it all seems ok-One thing though.. when it gets close to the cut off, i do hear sounds from the tank, that to me sound like a bladder releasing from something, itself or the side.

    I dont know whether it always has this sound but I just assumed that it acts like a balloon and when it gets to the higher pressure there shouldnt be any notable sounds of the bladder moving?
  9. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,126
    Location:
    NW Ontario, Canada
    Is the pressure switch on the tank Tee or otherwise close to the tank? Does the pump start and stop normally through the pressure range? Have you timed the cycles to see how long the pump runs and how long it stops? What time is the rapid cycle set to?

    If the cycles are short and frequent, you might want to consider a larger tank or a CycleStopValve.
  10. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    If you didn’t adjust the Rapid Cycle function of the Cycle Sensor, it is set at 30 seconds. If you are not getting at least 30 seconds of run time, something is wrong. Your pressure switch maybe too far from the tank, or you could have a faulty check valve. Rapid cycling and pumping the well dry are two of the worst things you can do to the pump. The Cycle Sensor will catch both of those things, but you need to solve the problem or the Cycle Sensor will keep tripping.
  11. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Hi

    My switch is close to the tank and the sensor was set at about 80, I have reduced it to 10 and it seemes to have stopped the rapid cycle error. I have tried at 40 and it still occurs but at 30 it seems ok so far

    the pump pumps for more than 30 seconds ( acouple of minutes maybe-. it seems to trip out when the pressure switch cut off activates.
  12. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Make sure your pressure switch is not double bouncing on shut off.
  13. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,126
    Location:
    NW Ontario, Canada
    Check to see if you are getting water hammer, perhaps from a bad checkvalve. That could make your pressure switch bounce.
  14. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    thanks for your perseverance guys

    LLigetfa-I am pretty sure I don't have a check valve and haven't noticed water hammer anywhere
    Valveman- Double bouncing? Is that simply looking at the contacts and seeing if they release and then reattach quickly?
  15. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Yes. If it is double bouning the contacts on pump shut off, then you probably have a bad check valve, like LL said, which you must have one of somewhere.
  16. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    thanks

    i will hunt for a check valve then-I guess it could be down the well?
  17. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    The Check Valve is usually on the pump itself. Also check to make sure you don't have too much air pressure in the tank. The tank bladder hitting the bottom can also cause the switch to bounce.
    Last edited: May 22, 2013
  18. warrens

    warrens New Member

    Messages:
    18
    Location:
    quebec
    Do you both agree therefore, that I probably don't have a hole in the pipe somewhere down the well-which is the issue I seemed to get often before I replaced the pumptech?
  19. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas

    The Cycle Sensor is supposed to go into RCYC when the pump shuts off, if the pump run time was not as long as the Rapid Cycle setting of the Cycle Sensor. In other words, if the Rapid Cycle feature is set for 30, the pump must run for at least 31 seconds before the presure switch shuts it off, or the Cycle Sensor will go into RCYC fault and not let the pump come back on.
  20. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,126
    Location:
    NW Ontario, Canada
    If you have a sticky checkvalve, you should notice some water hammer when the pump shuts off. Basically what happens is water starts to rush back to the well for a moment before the checkvalve slams shut. It also causes the needle on the pressure gauge to bounce. Take off the cover from the pressure switch and watch the contacts to see if there is bounce there. Could simply be a bad switch.
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