Wondered if anyone could help me figure out source of a sound coming from skimmer piping.
At random times (maybe every 3 days) I’ll hear a deep, rapid “thud” sound coming from the piping above ground that goes from skimmer to pump. You can feel the piping vibrate as this is occurring. If you look in skimmer basket area the water is at a standstill. At the pump there are air bubbles visible but hard to tell if it’s pumping anything, no odd noise from pump. As soon as you turn off pump & then turn back on right away the thudding is gone & all is well. Any ideas what may cause this? Pool runs ok otherwise. I’m thinking it’s some sort of air lock. The skimmer door is present & functions ok. Here’s pic of pool area in question, circled the piping with noise.

At random times (maybe every 3 days) I’ll hear a deep, rapid “thud” sound coming from the piping above ground that goes from skimmer to pump. You can feel the piping vibrate as this is occurring. If you look in skimmer basket area the water is at a standstill. At the pump there are air bubbles visible but hard to tell if it’s pumping anything, no odd noise from pump. As soon as you turn off pump & then turn back on right away the thudding is gone & all is well. Any ideas what may cause this? Pool runs ok otherwise. I’m thinking it’s some sort of air lock. The skimmer door is present & functions ok. Here’s pic of pool area in question, circled the piping with noise.
