I let someone vacuum my pool the other day, and they pulled it out without disconnecting it from the skimmer first. I noticed rather quickly because I heard a strange noise from the pump. I proceeded to re-start the system as if it was the first time for the year. The weird thing is now, if I open the pressure relief valve on the filter, no water or air spray from it. I backwashed the system thinking maybe the air that was sucked in did something to my grids. My pressure is back to normal, and my pool seems to be in good working order, but if I open the pressure relief valve, nothing happens. Should I be concerned?