Question
QUESTION: Thanks for providing this service.
We're on a well for our inground system, have a 1 1/2hp pump with a check valve installed on the inlet side, and a 6-zone FIMCO hydro-indexing valve. Lately when the system is running the pump loses prime and then corrects itself, then loses prime and corrects itself... over and over. What is the cause of this?

ANSWER: I would think that the check valve is not working right, or there is a leak in a fitting or pipe on the suction side of the pump.

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QUESTION: As far as the check valve goes..Is  fixing the problem a matter of just cutting the pvc pipe and installing another check valve?.  Does the system need to be primed and how is that done?

Answer
Its really hard for me to say, not knowing your particular setup.  But you would probably need to replace the check valve, whatever that entails.  Also, if you have a foot valve at the bottom of your suction line, check that as well.  It does involve pulling the line out of the well, so if the check valve repair works, you wont need to do it.