300' well. The pump runs fine for exactly 15 minutes, then shuts off for 1 minute, then comes back on. This has nothing to do with the pressure switch or anything above ground. It is being delivered power while it is off. The well pump with plenty of water.

Pump is approx 15 years old, I did not put it in. Water has low ph, but is good. Maybe thermal cutout in the pump? The pipe running down to the pump is galvanized, and is probably quite corroded due to the low ph. If I do replace it all this summer, what is the prefferred pipe material to use?

Thank you,

Jim P