An airlock in your pool pump is one of the most frustrating and common issues pool owners face. It disrupts water circulation, reduces the efficiency of your pool system, and can even cause damage to your pump if left unresolved. The good news is that fixing an airlock is usually a straightforward task—even for beginners. In this comprehensive guide, we’ll walk you through the process of diagnosing and resolving an airlock in your pool pump, helping you restore proper function and maintain a clean, healthy swimming pool.
Whether you’re a new pool owner or managing a commercial water system, understanding pool pump mechanics can help prevent further issues and extend the life of your equipment. Let’s dive in.
What Is an Airlock in a Pool Pump?
An airlock occurs when a pocket of air becomes trapped inside the pool pump’s housing or filter system, preventing water from flowing through properly. Water circulation is essential for distributing chemicals, filtering out debris, and maintaining overall pool quality. When air enters the system—typically through a loose fitting, cracked pipe, or a faulty seal—it blocks water’s path and stops the pump from priming.
Symptoms of an airlock include:
- The pump runs but doesn’t circulate water
- Unusual noises, like gurgling or loud humming, coming from the pump
- Visible bubbles in the pump basket or filter sight glass
- Poor filtration and cloudy pool water
Understanding these signs is the first step toward quick troubleshooting.
Common Causes of Airlocks in Pool Pumps
Knowing the cause of an airlock helps you fix it more effectively and, more importantly, avoid future occurrences.
Cracked or Loose Fittings
Connections between your pump, filter, and plumbing might develop leaks over time. Even a small crack or loose clamp can allow air to enter the system.
Low Water Level in the Pool
If your pool’s water level is too low, the skimmer may draw in air instead of water, creating bubbles in the pump system.
Leaks in the Suction Side Pipes
Any leak before the pump can introduce air into the water stream. Common areas include around pipe joints, valves, and the pump lid itself.
Improper Installation or Pump Placement
Sometimes, a pool pump installed too far from the pool or with poor pipe alignment can lead to inadequate water flow and eventual airlock formation.
Step-by-Step Guide to Fixing an Airlock in Your Pool Pump
This easy-to-follow process will guide you through correcting an airlock and restoring your pump’s optimal function.
Step 1: Turn Off the Pump
Safety comes first. Always shut off the electrical supply to your pump before inspecting or making repairs. This avoids risk of electrical shock and allows you to work safely and effectively.
Step 2: Check the Water Level in Your Pool
If the pool water level is below the midpoint of your skimmer, fill it until it reaches the proper level. A low water level is a leading cause of airlocks, so this may resolve the issue on its own.
Step 3: Remove the Pump Lid and Fill the Housing with Water
Most pool pumps have a lid covering the strainer basket. Carefully unscrew and remove the lid. You may find the housing partially or completely empty of water.
Rinse out any debris or hair stuck on the basket, then refill the housing with clean pool water using a hose or bucket. Replace the lid securely to ensure it’s watertight.
Step 4: Release Air Through the Filter’s Bleed Valve
Your pool filter should have an air bleed valve (sometimes called a pressure relief valve). Open this valve before turning the pump back on—this allows trapped air to escape as the pump builds pressure.
If you do not see an air bleed valve, check for a clear plastic tube near the top of your filter or consult your filter’s manual for the correct procedure.
Step 5: Prime the Pump
Restart the pump and observe the water flow. If done correctly, the pump should begin drawing in water again, forcing the trapped air out through the bleed or return line.
Wait two to five minutes for the system to fully prime. Watch for steady water flow, bubbles decreasing, and the pressure gauge on the filter to rise to a normal level.
How to Prevent Future Airlocks in Your Pool System
Preventative maintenance is key to avoiding repeat airlock issues and prolonging the life of your pool components.
Regular Inspections and Tightening
Check all pump and filter connections weekly. Use clamps where necessary, replacing any that show signs of corrosion or wear. Tighten threaded fittings and replace older gaskets as needed.
Sealing Suction-Side Leaks
Seal exposed pipes and fittings on the suction side of the pump with waterproof pool pipe sealant or silicone. If you suspect a leak, perform a soap test by applying a soapy water solution to connections. If bubbles form while the pump is running, that’s where air is entering.
Maintain Proper Water Levels
Set a reminder to visually inspect your pool’s water level weekly, especially during periods of high evaporation or after heavy rain. Water should always cover skimmer intake ports.
Professional Maintenance and System Checkups
Schedule annual or bi-annual professional servicing of your pool equipment. Certified technicians can identify small cracks, early seal wear, and other early-stage issues that could lead to airlocks over time.
What to Do If the Airlock Persists
If you’ve followed all the correct steps and your pump still isn’t priming or moving water effectively, deeper issues may be at play. Here’s how to identify and address them.
Check for Filter Blockage
A clogged filter can also mimic the symptoms of an airlock. Remove the filter and rinse or replace it, depending on the type—sand, cartridge, or DE (diatomaceous earth). Clean filters allow efficient water flow and reduce pump strain.
Inspect the Pump Impeller
If the impeller inside your pump is clogged or broken, water won’t flow correctly. Turn off the power, remove the impeller cover, and clear debris or mineral buildup. If the impeller is damaged, replacing it is often more cost-effective than repairing.
Identify and Repair Underground Leaks
If your suction lines run underground, persistent airlock problems may stem from cracked pipes beneath the surface. Look for signs like wet spots in your yard or a drop in water level unrelated to evaporation. Professional leak detection services can help in these cases.
Consider Upgrading Your Pump System
If you’re suffering from frequent airlocks and poor performance despite maintenance, it may be time to consider a new or upgraded pump and filter system. Newer models often come with better seals, quieter operation, and advanced diagnostics.
When to Call a Professional Pool Technician
While many airlock issues can be resolved by careful troubleshooting and maintenance, some situations call for expert intervention.
Recurring or Severe Airlock Problems
If airlocks continue to occur frequently despite basic fixes and preventive measures, you may have a complex leak or system flaw that requires the experience of a pool technician.
Inaccessible or Hidden Components
Pools with complex plumbing systems or those connected to automation systems require careful inspection that isn’t always accessible to homeowners.
Electrical or Warranty Concerns
Always consult a professional if you’re unsure what electrical steps are safe, especially if your system involves timers, variable-speed pumps, or automation. Tampering with some systems may also void warranties if not handled correctly.
The Costs of Fixing an Airlock Issue
Knowing what your budget should be helps you decide whether to DIY or hire a technician.
DIY Costs
Fixing an airlock usually requires minimal expense:
- New o-rings or pump seals: $10–$30
- Cartridge or sand media replacement: $20–$150 depending on type
- Hardware repairs like pipe sealants: under $10
This makes it a very cost-effective option when compared to professional services.
Professional Service Costs
Calling a technician may cost anywhere from $50 to $200 for a routine diagnostic and repair visit. More complex issues—like pipe leaks or motor damage—could run into several hundred dollars.
Conclusion: Take Control of Your Pool Pump Maintenance
Airlocks are more than just a nuisance—they can lead to more serious inefficiencies and pool equipment damage if ignored. The good news is that, with the steps outlined above, most airlocks can be resolved quickly without professional help.
By understanding how your pool pump works, learning how to spot and fix airlocks, and performing regular maintenance, you’ll ensure healthy water flow, chemical balance, and extended equipment life.
So the next time your pump sounds unusual, or your water looks cloudy despite regular cleaning, follow these troubleshooting procedures before calling a technician. You’ll save time, money, and the headache of a stalled pool season.
With a little knowledge and vigilance, you’ve got all the tools you need to maintain a clean, efficient pool system all year round.
What is an airlock in a pool pump and why is it a problem?
An airlock occurs when air becomes trapped in the pool pump or the suction lines, preventing water from flowing through the system properly. This blockage disrupts the priming process, which is essential for the pump to circulate water through the filter and back into the pool. Without proper water circulation, your pool can become stagnant, leading to algae growth, poor filtration, and potential damage to the pump motor due to overheating.
This issue often arises after the pool system has been drained or when there’s a leak in the suction side of the pump. Identifying and resolving an airlock quickly is crucial to restore the system’s functionality and avoid long-term damage. Understanding how airlocks form helps pool owners take preventive measures, such as regularly checking for leaks or ensuring the pump lid seals properly after maintenance.
How can I tell if my pool pump has an airlock?
Common signs of an airlock in your pool pump include a noisy pump (such as a whining or gurgling sound), reduced water flow through the system, and failure of the pump to prime. You might also notice air bubbles in the sight glass or pump basket, and the pressure gauge on your filter may read lower than normal. These symptoms usually appear when the pump is unable to draw enough water due to trapped air.
Sometimes, airlocks are mistaken for other issues like low water levels or clogged filters. If your pool has recently undergone maintenance or the pump was turned off for an extended period, an airlock is more likely the root cause. Observing these indicators closely can help you make a faster diagnosis and begin troubleshooting without unnecessary repairs.
How do I manually prime the pump to remove an airlock?
To manually prime your pool pump, begin by ensuring the pump is turned off and remove the pump lid. Fill the pump basket with water using a hose or bucket, making sure the interior is completely submerged. Replace the lid securely, then turn on the pump while opening the air relief valve located on the filter. Water should begin exiting through the valve once the air is purged.
Manual priming works best for smaller airlocks and is most effective when your pump and filter system is relatively airtight. If your pump is still struggling to pull water after priming, turn off the system and recheck for air bubbles in the basket. You may need to repeat the process or inspect other components like the lid O-ring or plumbing connections for leaks that might reintroduce air.
What steps should I take if the pump continues to lose prime after fixing the airlock?
If your pump continues to lose prime even after removing the airlock, turn off the equipment and inspect the pump lid O-ring for wear or damage. A faulty O-ring can allow air to re-enter the system. Next, check the pump basket lid to ensure it’s sealing properly—debris or cracks can prevent a tight seal. Additionally, inspect the valves and plumbing on the suction side of the pump for leaks or loose connections.
If none of these seem to be the issue, consider whether there’s a problem with the pool’s water level. Water levels that are too low can cause the skimmer to suck in air instead of water. Also, it’s worth checking the impeller for clogs or damage, as a malfunctioning impeller can affect the pump’s ability to maintain pressure and circulate water effectively. These steps help identify and address more persistent causes of recurring airlocks.
Can using a wet/dry vacuum help remove a stubborn airlock?
Yes, a wet/dry vacuum can be an effective tool for removing a stubborn airlock when conventional priming doesn’t work. Set the vacuum to blow mode and attach the hose to the skimmer’s suction port or the return jet, sealing it tightly with a plastic bag or tape. Turn on the vacuum to force air through the lines, which can help dislodge trapped air bubbles in the plumbing.
Using a wet/dry vacuum should be a temporary fix and not a regular maintenance method. The high pressure it generates can cause strain on older pipes or fittings. It’s also important to ensure the vacuum is in good working condition and that the method is performed carefully—using the correct mode is crucial, as sucking air out rather than blowing it in could make the problem worse.
What maintenance practices can help prevent airlocks in the future?
To prevent airlocks, regularly inspect your pool pump system for leaks, especially around the pump lid, O-rings, and suction-side plumbing. Tighten loose connections and replace worn components like the pump lid O-ring or basket lid. Maintaining the proper water level in your pool—about halfway up the skimmer opening—ensures the skimmer can effectively draw water without pulling in air.
Additionally, always prime the pump after performing maintenance, even if you believe it wasn’t drained completely. Keeping a maintenance log can help you track repairs and part replacements, making it easier to anticipate when something may fail. Being proactive about system integrity and regular pump inspections can significantly reduce the chances of encountering airlocks.
When should I call a professional for help with an airlock issue?
If you’ve tried multiple troubleshooting techniques like manual priming, using a wet/dry vacuum, and checking for leaks but still experience persistent airlocks, it may be time to call in a professional. Also, if you suspect the issue lies deeper in the plumbing or involves equipment failure—such as a cracked impeller, broken check valve, or underground line leaks—a qualified technician can properly diagnose and resolve the issue.
Professionals have access to tools like pressure gauges, specialized leak detectors, and equipment diagnostics that may be out of reach for the average pool owner. Attempting to fix major problems without proper knowledge can lead to further damage or void manufacturer warranties. If you’re unsure of the root cause and the problem keeps recurring, seeking expert help is the best solution to ensure long-term performance of your pool system.