On Feb 11, 4:18*am, RSC wrote:
The pump is submersible and the bang happends right when it starts. *I
can't realy tell where it's comming from. *I put my ear on the tank
and my hand on the check valve and still the whole thing just bangs.
No pipes touching a wall. *I will replace the check valve, that makes
the most sense.

RSC

Thanks

Shouldn't be (but commonly is) a checkvalve except for the one built
into the pump.

Harry K