Hi all,

Fairly new to being on a well and need some advise on a problem.
Have a submersible pump approx 12 years old, a 2 year old Flotec bladder tank and a pressure swich setting of approx 40/55. Pump has been cycling with no water usage - I isolated house/irrigation system from line - pressure still drops, to zero given approx 2 hours when breaker turned off. Tank shows 20psi when empty, no leaks detected around tank, pressure switch or pump/piping itself.I am hearing water hammering when the pump cycles. Where's the best place to start? I do have a check valve at the well head, should I replace it? Line from pump to house is underground but fairly short ((30ft) Any help would be appreciated.