How To Get Air Out Of A Pool Pump: Step-by-Step Priming And Troubleshooting Guide

To get air out of a pool pump, you must bleed the air from the filter's air relief valve while the system is running, or manually prime the pump pot by filling it with water and sealing the lid tight if it has lost prime entirely. Successfully clearing air locks prevents impeller damage, stabilizes system pressure to its normal baseline of 10 to 15 PSI, and restores full circulation to your pool filtration system.

An efficient pool filtration system relies entirely on a continuous, uninterrupted loop of water. Because pool pumps are centrifugal, they are designed to move water, not air. When air enters the system, it collects in the pump pot and filter tank, causing the pump to lose its prime. This drops circulation, raises operational temperatures, and can quickly melt internal plastic components or burn out the shaft seal.

To resolve this issue permanently, you must understand the distinction between the suction side and the pressure side of your pool. Air leaks only occur on the suction side (everything before the pump impeller, including the skimmer, main drain, valves, and pump lid) because this zone is under negative pressure, which actively draws air in. The pressure side (everything after the impeller, including the filter, heater, and return jets) is under positive pressure, meaning leaks here will manifest as escaping water rather than entering air.

Pre-Priming Diagnostics and Essential Pool Tool Checklist

Before attempting to bleed air or prime your pump, you must identify whether you are dealing with a temporary air lock (common after cleaning the pump basket) or a persistent suction-side air leak. Working on a pressurized pool system carries inherent physical risks. Always verify that the filter’s pressure gauge is functional before beginning any procedure.

Essential Tools and Materials

• Silicone-Based Lubricant: Designed specifically for pool O-rings (e.g., Jack’s Multilube). Never use petroleum-based lubricants like Vaseline, as they degrade rubber seals.
• Garden Hose: Connected to an active, high-flow water source.
• Stiff Utility Brush or Microfiber Rag: For cleaning the pump lid groove and O-ring channel.
• Replacement Pump Lid O-Ring: A backup matching your specific pump model (common models include Hayward Super Pump, Pentair WhisperFlo, or Jandy FloPro).
• Strap Wrench (Optional): Helpful for removing stubborn, overtightened pump lids.

Prerequisite Knowledge & Operating Standards

• Pool Water Level: The water in your pool must be at least halfway up the skimmer mouth opening. If it is lower, the skimmer will draw in air, creating a vortex and making priming impossible.
• Electrical Safety: Ensure you know the location of the main pool equipment circuit breaker. Never service the pump pot or open the lid while the pump motor is energized.
• Normal Operating Pressure: Familiarize yourself with your filter's clean operating pressure, which typically ranges between 10 and 15 PSI (pounds per square inch) depending on your plumbing layout.

Estimated Resource Benchmarks

• Time Required: 15 to 30 minutes.
• Estimated Budget: $0 (basic re-priming) to $25 (if replacing dry-rotted O-rings or buying pool lube).

Step-by-Step Guide to Bleeding Air and Priming Your Pool Pump

Follow this precise sequential workflow to safely evacuate air from your pool pump and filtration plumbing.

Step 1: Power Down and Safely Depressurize the System

Turn off the pool pump immediately at the control panel or breaker. Do not rely solely on automated timers, as they may reactivate the pump mid-procedure.

Locate the manual air relief valve on top of the pool filter tank. Slowly turn the valve counterclockwise to open it. You will hear a loud hissing sound as pressurized air escapes. Leave the valve open until the pressure gauge on top of the filter drops to exactly 0 PSI and water ceases to drip from the valve.

Warning: Never attempt to open the pump lid or disassemble any plumbing joints while the system is pressurized or while the air relief valve is closed. High pressure can cause the pump lid or filter clamp to blow off with explosive force, causing severe bodily injury.

Step 2: Position Your Valves for Optimal Water Draw

Adjust your suction-side valves to concentrate the water draw. If your pool has multiple suction lines (e.g., two skimmers and a main drain), close the skimmer valves partially and open the main drain line completely, or isolate a single skimmer line that you know is completely submerged.

If your filtration system utilizes a multiport valve, ensure it is set to the standard "Filter" position. If you are dealing with a severe air lock and need to bypass the filter entirely to get water moving, you can temporarily turn the multiport valve to "Recirculate."

Step 3: Inspect, Clean, and Lubricate the Pump Lid and O-Ring

Remove the pump lid by unscrewing the locking ring, T-bolts, or lock-nut handles. Carefully lift the basket out and dump any leaves, twigs, or organic debris. Inspect the plastic basket for cracks or structural failures; a cracked basket can allow debris to pass through and clog the pump impeller.

Remove the rubber O-ring from the pump lid or the groove inside the pump pot. Wipe it completely clean using a damp microfiber cloth. Inspect the O-ring for fine cracks, dry rot, flattening, or stretching. If the O-ring is damaged, replace it immediately. If it is in good condition, apply a generous, even coat of silicone-based pool lubricant across its entire surface. Clean the mating surface on the pump pot where the O-ring sits to ensure no sand grains or pine needles interfere with the seal.

Pro-Tip: Over time, the plastic threads or locking tabs on your pump lid can wear down. When putting the lid back on, tighten it hand-tight only. Do not use a mallet or metal tools to tighten the lid, as this will warp the plastic, split the O-ring, and create a permanent path for air leaks.

Step 4: Manually Flood the Pump Pot

Insert the garden hose directly into the pump basket housing. Turn the water on high and let the hose run until the water rises to the absolute brim of the pump pot, overflowing into the suction line leading back to the pool. This manual flooding is critical because it provides the initial mass of water the impeller needs to generate centrifugal suction and draw water all the way from the pool.

Once the pot is completely filled, quickly remove the hose, place the lubricated O-ring back in its designated slot, and seal the pump lid tightly. Speed is important here to prevent the water from draining back down the suction pipes.

Step 5: Power On and Bleed the Rest of the Air

With the pump lid sealed tight and the filter's air relief valve still open, turn the power back on to the pool pump.

As the pump starts, you will hear gurgling and splashing inside the pot. Watch the water level through the transparent lid. The air relief valve on the filter will begin spitting a mixture of air and mist. Maintain your position next to the filter with your hand on the air relief valve.

Within 30 to 60 seconds, water should rush into the pump pot, filling it completely so that it looks like a clear, bubble-free pane of glass. Once the pump is fully primed, a solid, continuous stream of water will shoot out of the filter's open air relief valve. Immediately close the valve by turning it clockwise until it is hand-tight.

Pool Filtration Operating Pressures and Component Tolerances

To maintain a healthy, air-free circulation loop, your pool equipment must operate within precise physical parameters. The table below outlines key operational baselines, failure limits, and physical indicators of air infiltration.

Identifying and Resolving Persistent Air Leaks in Your Filtration System

If you have completed the priming steps and air continues to accumulate in your pump pot, you have a suction-side air leak. Use the diagnostics below to locate and repair the root cause.

• Scenario 1: The pump loses its prime immediately after the motor shuts down.

  
  
  
  • Root Cause: The suction-side plumbing or pump lid is not airtight, or you have a failing check valve. When the pump turns off, gravity pulls the water back toward the pool. If there is even a microscopic air leak above the water line, air is drawn in to replace the falling water, draining the pump pot.
  • Actionable Fix: Replace the pump lid O-ring and apply fresh silicone lubricant. If your pool equipment sits higher than the pool's water level, inspect, clean, or replace the check valve installed on the main suction line to prevent backflow.

• Scenario 2: A constant stream of small bubbles shoots out of the pool return jets.

  
  
  
  • Root Cause: A minor, persistent suction-side leak is pulling air into the system continuously. This is most commonly found at the threaded PVC male adapter leading directly into the front nose of the pump, or at the stem O-rings of your 3-port Jandy valves.
  • Actionable Fix: Run a "shaving cream test." Apply thick shaving cream to the threaded plumbing connections at the front of the pump and around the valve stems while the pump is running. Watch for a spot where the shaving cream is sucked into the plumbing. Once found, cut and rebuild the joint with fresh PVC primer and glue, or replace the internal valve stem O-rings.

• Scenario 3: The pump pot remains half-empty, and the water inside is churning violently.

  
  
  
  • Root Cause: The system is starved for water, meaning the suction side is restricted, or the water level in the pool is too low. A stuck skimmer weir door (the floating flap) can also lock in an upright position, blocking water flow and forcing the pump to suck air.
  • Actionable Fix: Add water to your pool until it reaches the midpoint of the skimmer mouth. Check the skimmer weir door; ensure it moves freely on its hinges. If it is stuck, sand down any swollen plastic edges or replace the spring pins.

• Scenario 4: Filter pressure remains incredibly low (below 5 PSI), and the pump won't pull water even after manual priming.

  
  
  
  • Root Cause: The pump impeller is clogged with debris, or there is a severe blockage deep inside the underground suction lines.
  • Actionable Fix: Shut off the power breaker. Remove the pump lid and basket. Reach through the throat of the pump into the impeller eye with your fingers or a stiff wire. Clear out any compacted leaves, pine needles, or pebbles. If the impeller is clear, clear the suction line using a pressurized bladder tool (such as a "Drain King") inserted into the skimmer pipe.

Frequently Asked Questions

Is it dangerous to run a pool pump with air inside?

Yes, running a pool pump with air instead of water can cause catastrophic damage within minutes. Water acts as a crucial cooling agent for the pump's internal components, specifically the mechanical shaft seal; running dry causes extreme friction heat that can melt the plastic impeller, warp the pump basket, and destroy the motor.

Why does my pool pump keep getting air in it overnight?

This is caused by a slow suction-side leak that only manifests when the system is turned off. Gravity pulls the water column back down into the pool, drawing air in through the weakest point—usually a dry pump lid O-ring, a loose union joint, or a worn valve stem seal—which completely empties the pump pot before the next run cycle.

How long should it take for a pool pump to prime and clear air?

A properly sealed and flooded pool pump should prime and clear all major air pockets within 30 to 90 seconds. If your pump runs for more than two minutes without pulling water and purging the air, turn it off immediately to prevent heat damage and re-verify your water levels and suction valve positions.

Should there be any air under my pool pump lid during normal operation?

In a perfectly sealed system, there should be no air visible under the pump lid; the pump pot should be completely packed with solid, moving water. A tiny air bubble the size of a coin is normal and harmless, but any pocket of air that exposes the top of the pump basket indicates a suction-side leak that needs to be addressed.

Restore Your Pool's Circulation Today

Ensure your pool filtration system operates at peak efficiency by maintaining airtight seals and proper water levels. If you are struggling with persistent air leaks, need replacement pump components, or require professional plumbing diagnostics, contact our expert team today to schedule an on-site system inspection.