Why Your Pool Pump Is Sucking Air
If you notice:
Bubbling or gurgling sounds in the pump
Air in the pump basket
Low or uneven water flow
Water level dropping below the skimmer
…it usually means air is entering the pump system somewhere it shouldn’t.
Here are the main reasons why:
1. Low Water Level in the Pool or Skimmer
If the water drops below the skimmer opening, the pump will pull in air.
Check the water level: it should be about halfway up the skimmer.
Hot weather, evaporation, or heavy splash-out can lower the level enough for air to get in.
2. Loose or Leaking Pump Lid O-Ring
The pump basket lid has a rubber O-ring to seal the pump.
If the O-ring is cracked, dry, or not seated properly, air can be sucked in.
Look for bubbles in the pump basket or water dripping from the lid.
Tip: Clean and lubricate the O-ring with pool-grade silicone grease.
3. Leaks in the Suction Side Plumbing
Air can enter anywhere before the pump impeller:
Cracked or loose pipe fittings
Worn unions or joints
Damaged skimmer baskets or gaskets
Check for hissing sounds or visible leaks on all pipes leading to the pump.
4. Clogged or Blocked Skimmer
Leaves, debris, or skimmer baskets that are too full can restrict water flow, causing the pump to draw air.
Make sure the skimmer basket is clean and free-flowing.
5. Pump Running Dry
If the pump is turned on before being primed, it can suck air and lose prime.
Always fill the pump basket with water when restarting the pump.
6. Faulty Check Valves or Pool Equipment
Automatic water features, solar panels, or check valves can sometimes trap air in the suction line.
A malfunctioning valve may allow air to leak into the pump system.
How to Fix a Pump Sucking Air
Check and raise the water level if needed.
Inspect and reseat the pump lid O-ring; replace if cracked or worn.
Look for leaks in all suction-side plumbing, including skimmer gaskets.
Clean skimmer baskets and pump basket.
Prime the pump properly after maintenance.
If the problem persists, call a professional to inspect for hidden leaks or cracked pipes.
💡 Key Tip:
A pool pump sucking air can reduce flow, stress the pump motor, and eventually damage your equipment. Fix it as soon as you notice it.