If your pump stops pumping, touch it to see if it is running. You will feel it humming. If it is, check hoses. Unplug the pump and look at the impeller to see if something is stuck in there. If it is not running, check your GFCI outlet. You do have one, don't you? If not, get one. If so, push the button to reactivate the circuit. If it does not come back on, you probably have a defective pump. If the circuit continues to break, let it dry out and try it again.
Submersible pumps have a safety switch built in that turns the pump off when it gets too hot. Intermittent starting and stopping means your pump is getting too hot, shutting itself off and when it cools, it is starting again. Soon your pump will stop altogether having burned out. Start planning for a new pump as soon as your pump begins its intermittent behavior.
If the impeller is not spinning freely, check to see if there is junk in there. Remove the junk with a screwdriver and keep moving the impeller with the screwdriver until the impeller moves freely.
To learn more tricks and tips like this one, download my book, "A Practical Guide to Building and Maintaining a Pond" here
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