Hello! Just installed a well and well pump three months ago. All brand new. Today heard a hammering noise outside. Traced the noise to our basement and noticed the pressure gauge needle was jumping and making noise in the lines and shaking the lines every second. I installed a used pressure tank and assumed the bladder went bad so I went to Lowe's bought a new tank, just installed it, and the noise is still there. As soon as the water is used in the house and the pressure drops and kicks on at 30. The hammering stops until the needle reaches 50 and as soon as pump kicks off, the hammering and needle jumps again. Please help.

What type of pump, submersible or above ground?
Apparently your pump switch is set to 30/50. Was the new tank pressurized or did you pressurize it to 28 lbs? Remove switch cover. Is switch points opening and closing when the hammering occurs?

Harold. I will look in the morning. I noticed after I posted that if I leave the pump on. And only allow the water to fill the pressure tank, the pressure needle will drop from 50-30 within 5 minutes. I think I have a leak in the line.

And the ground us frozen here in NY until spring. I was thinking of installing a check valve temporarily until spring. This should buy me some time I hope.

And I did set it to 28 pounds.

Thanks in advance.

Harold if your still up I can check that now. Let me know.

And it's a well pump 55 feet down in well casing

Sounds like you have a leaking foot valve. As soon as the pump stops, water begins flowing back down the well and causes the pump to come on again.

Depending on how cold and how deep the pipes are buried you may have a busted pipe between the house and the well. A leaking pipe from freezing should have show up as a period of no water. Should also show up again with the expected weather in the nest week. Check valve should fix things if it is a leaking foot valve.

Would a check valve in the basement be a temp fix for now? Thus stopping the water from leaking back after the pump brings it to the pressure tank?

Yes, I was modifying my post at same time you were posting.

So your saying I can use a check valve until the ground thaws until I can find the leak? Temp only.

Yes, check valve would substitute for leaking foot valve. If you have a busted pipe from freezing it would have taken a long time to thaw. If you have a leaking pipe and install a check valve you may (or may not) start getting air out of faucets after a period time. As water leaks out and air enters the pipe, the air will get pushed into the tank and causing burst of air out of faucets.

OK. Thank you for your help.