I have a 3 year-old Hayward Powerflow-max SP-1510-Z1-XEHC pump on my 18 foot above ground pool and a DE filter. I replaced a hose today and had the skimmer and discharge plugs in. I had everything hooked back up and was ready to go. Had my wife turn on the pump. The pump sounded like it needed priming. When I checked it, I noticed the suction hose was sucked tight. I realized immediately that I forgot to remove the plugs and yelled to my wife to shut off the pump. The pump ran for about 10 seconds or so. I took the plugs out. The skimmer plug I had to remove with a wrench due to the vacuum the pump had put on it. After removing the plugs. We tried starting the pump again. This time, the motor started making a humming sound but did not rotate the pump. I rotated the impellar and it appears to rotate freely. Any ideas what is likely the cause.