How to Fix a Swimming Pool Pump That is Sucking Air (Step-by-Step Guide)

If you walk out to your backyard, look at your pool pump’s clear lid, and see a massive swirling vortex of air instead of smooth, crystal-clear water, you’ve got a problem. Your pool pump is sucking air.

When this happens, the pump loses its prime, the water filtration stops, and if you leave it running bone-dry for too long, you risk burning out an expensive motor.

Don't panic and call a pool technician just yet. As a DIYer, 90% of the time, you can fix this issue in less than 30 minutes with basic tools. Let’s roll up our sleeves and fix it.

Step 1: Check the Pool Water Level (The Easiest Culprit)

Before you start tearing the pump apart, look at your pool's skimmer. If your pool water level is too low—specifically below the halfway mark of the skimmer opening—the skimmer will create a whirlpool effect. It will literally gulp air straight into the pipes.

The Fix: Grab your garden hose and fill the pool up until the water level rests exactly at the midway point of your skimmer tile.
Check the Weir Door: Ensure the plastic flap (weir door) inside the skimmer isn't stuck in the upward position. If it gets jammed, it blocks water flow and forces the pump to suck air.

Step 2: Inspect and Lubricate the Pump Lid O-Ring

If your water level is fine, the most common culprit is a dried-out, cracked, or dirty pump lid O-ring. The pump operates under vacuum pressure; even a microscopic gap in that rubber ring will act like a straw with a hole in it.

Turn off the pool pump completely at the breaker.
Twist off the clear pump lid and remove the rubber O-ring.
Clean the O-ring and the groove inside the pump with a clean rag. Check for tiny cracks or flattened spots. If it's cracked, replace it.
Pro Tip: Never use petroleum jelly (like Vaseline) on your pool O-rings! Petroleum degrades rubber over time and destroys it. Instead, apply a generous coat of a silicone-based pool lubricant (like Jack's Multilube) to keep the seal airtight.
Seat the O-ring back in place, put the lid on, and hand-tighten it securely. (Do not overtighten with tools).

Step 3: Check the Skimmer Basket and Drain Plugs

A heavily clogged skimmer basket restricts water flow so drastically that the pump will claw for anything it can get, forcing air through small gaps.

Empty any leaves, twigs, or debris from both the skimmer basket and the pump’s strainer basket.
Check the pump housing drain plugs (the little plastic screws at the bottom of the pump used for winterization). If these plugs are loose or missing their tiny O-rings, air will leak in from the very bottom of the unit. Thread them tightly with a bit of Teflon tape if necessary.

Step 4: Look for Plumbing Leaks on the Suction Side

If you are still seeing bubbles in the basket, the leak is likely in the PVC pipe joints coming out of the ground into the front of the pump (the suction side).

The Shaving Cream Trick: Turn the pump on. Take a can of thick shaving cream and slather it all over the PVC pipe joints and the valves in front of the pump. Watch closely. If the pump sucks the shaving cream into a joint, you’ve found your air leak!
The Fix: Clean the leaky joint thoroughly and apply PVC primer and glue, or use a specialized pool sealant epoxy to seal the gap while the pump is off.

Summary for Homeowners

Fixing a pool pump that sucks air doesn't require an engineering degree. Start with the simplest solutions: fill your water, grease that lid O-ring with silicone lube, and clear out the debris. Keep your suction lines airtight, and your pool will be running crystal clear all summer long.