Check valve making a loud bang at end of cycle
I just replaced my sump pump because the old one would not shut off and it was 8 years old. I had to replace the pvc piping coming out of the pump that comes up and out of the pit. I did not drill a 'relief hole' in the new pipe(the old pipe had one), could this be causing excess pressure that is making the check valve bang? If so where should I drill the whole, and does it matter at what angle it is drilled?
If not any suggestions? I've never had a basement before and I don't know if its time to bring a plumber out(I would prefer to try to fix it myself)