airlocks in water pumps

May 21, 2025
By BISON

Air locks in a water pump can hinder water flow and affect its operation. This occurs when air is trapped in the system, preventing the pump from pumping water efficiently. Common symptoms include low water pressure, broken pipes, or no water flow.

Preventing and resolving air lock issues is essential to maintaining the performance and life of your water pump, ensuring it can effectively meet the needs of a variety of applications.

Fortunately, there are several ways to clear air locks in a water pump. BISON will walk you through the causes, signs, and troubleshooting steps of air locks to help you restore the functionality of your water pump.

Understanding water pump airlocks

An airlock occurs when air becomes trapped in a water pump system, preventing it from drawing water effectively. This can result from several causes, including:

Low water levels: Insufficient water to fully submerge the pump can introduce air, causing an airlock.
Leaks in the suction line: Leaks allow air to enter, particularly in the suction line, which can disrupt the pump’s operation.
Clogged foot valves: Obstructions can trap air within the system, leading to an airlock.
Installation issues: Improper pipe angling can trap air pockets within the pump system.
Recent maintenance or system changes: Cleaning, repairs, or part replacements can disturb the system and introduce air.
Pressure and temperature changes: Variations in pressure or temperature can cause dissolved gases to form air bubbles.
Pump design and pipe layout: Certain designs or layouts may not provide proper venting, making airlocks more likely.

Airlocks can cause significant issues, impacting both the efficiency and longevity of the pump system:

Reduced efficiency: Air bubbles disrupt water flow, reducing the pump’s capacity to deliver the required volume.
Lowered pressure: Air compresses more easily than water, reducing the pump’s pressure output.
Increased energy consumption: The pump works harder to move the air-water mixture, resulting in higher energy use and strain on the motor.

While airlocks are not immediately dangerous, they must be addressed promptly to avoid long-term damage.

Overheating: Reduced flow and increased workload can cause the motor to overheat, potentially leading to failure.
Wear and tear: Air causes vibrations, accelerating wear on components like impellers and seals.
Cavitation: Air bubbles collapsing within the pump can cause cavitation, eroding pump components.
Increased maintenance: Persistent airlocks increase maintenance needs, including system bleeding, leak checks, and parts replacement.
Impact on other systems: If interconnected, an airlocked pump can disrupt downstream systems, causing cascading operational issues.

Identifying an airlocked water pump

Recognizing the symptoms of an airlocked water pump is crucial for timely intervention and to prevent potential damage. Airlocks can severely impede a pump’s performance, so understanding the signs is essential for effective troubleshooting. Common symptoms of an airlocked water pump:

Pump running without water (dry running): The pump operates, but no water is delivered. Running dry can cause overheating and damage internal components due to the lack of lubrication and cooling from water.
Strange noises: Air pockets disrupt the normal flow of water, causing turbulence and vibrations inside the pump. Unusual sounds like gurgling, rattling, or humming may be heard from the pump.
Overheating: Without proper water flow, the pump cannot dissipate heat effectively, leading to overheating.
Low water pressure or no water flow: Airlocks block the water’s passage, reducing pressure and flow rates.
Ineffective self-priming: The airlock prevents the pump from properly priming itself.

Fixing an airlocked water pump: A step-by-step guide

Dealing with an airlocked water pump can be frustrating, but with the right approach, you can often resolve the issue yourself. Follow this step-by-step guide to troubleshoot and fix an airlocked pump:

Procedures before removing the airlock

To ensure safety and protect the plumbing system, follow these essential steps before removing the airlock from your water pump:

Disconnect the power supply to the pump. This will prevent electric shocks or damage to the motor during the airlock removal process.
If the system is pressurized, open a faucet downstream to release the pressure before working on the pump.
Prepare the necessary equipment such as pliers, a wrench, and a bucket to hold water. Having the right equipment ready will make the process faster and easier.
Always consult the pump’s user manual for specific guidance on removing airlocks. Different pumps may have unique procedures, so it’s important to follow the manufacturer’s recommendations.

Method 1: Using a bleed valve

One effective way to remove an airlock in a water pump is by using the bleed valve, which is designed to release trapped air from the system. Here’s how to do it:

Locate the bleed valve: The bleed valve is typically found on top of the water pump or along the plumbing line connected to the pump. Make sure it is easily accessible.
Prepare a container: Place a container, such as a bucket, beneath the bleed valve to catch the water and air that will be released.
Open the valve slowly: Use a wrench or pliers to slowly open the valve counterclockwise. Open it carefully to avoid a forceful splash of water.
Release the trapped air: As you open the valve, you will hear a hissing sound, which means air is being released. Continue opening the valve until a steady stream of water flows without any air bubbles.
Close the valve: Once the air is fully released and the water flows steadily, turn the valve clockwise to close it.
Turn on the pump: After closing the valve, restore the power supply to the pump and check if the water flow resumes without issues.

Method 2: Changing the water flow

If the bleed valve method doesn’t work or your pump lacks a bleed valve, you can try reversing the water flow to remove the airlock. This method uses an external water source to flush trapped air out of the system. Follow these steps:

Prepare an external water source: Connect a hose to a faucet or water source separate from the pump system. Ensure the hose is long enough to reach the pump’s intake or supply line.
Connect the hose: Attach one end of the hose to the external water source and the other end to the pump’s intake or supply line. Tighten the connection to avoid leaks.
Turn on the external water source: Open the faucet or valve to allow water to flow through the hose and into the pump system, creating pressure to force the air out.
Purge the air: As water moves through the system, you should see air bubbles coming out of the pump. Continue until a steady water flow is achieved without bubbles.
Disconnect the hose: Once the airlock is cleared and water flows freely, turn off the external water source and disconnect the hose from the pump.
Turn on the pump: Finally, turn on the pump and check if the water flow returns to normal, confirming that the airlock has been removed.

Method 3: using manual priming

This technique involves manually pumping water into the system to expel the trapped air. Follow these steps:

Locate the priming port: Find the priming port on the water pump, which is usually a small opening that allows water to enter the system manually.
Prepare a container of water: Fill a bucket or container with clean water that you’ll use to prime the pump.
Immerse the priming port: Submerge the priming port in the container of water, ensuring the port is fully covered.
Turn on the power: After immersing the priming port, turn on the pump’s power supply.
Activate the pump: Activate the pump by switching it on. The pump will draw water through the priming port into the system.
Monitor water flow: Watch the water flow from the pump. Initially, you’ll see air bubbles, but keep the pump running until a steady flow of air-free water is achieved.
Close the priming port: Once the airlock is removed and water flows steadily, turn off the pump and close the priming port.
Switch on the pump: After closing the priming port, switch the pump on again and check if the water flow is restored to normal.

Conclusion

A water pump’s airlock can be annoying because it obstructs water flow and impairs pump performance. However, with the right information and techniques, you can remove the airlock and resume regular water flow.

This blog post examined several approaches to clearing air locks in water pumps, such as manual priming, reversing water flow, and utilizing a blade valve. Considering your water pump’s unique circumstances and features, each technique has benefits and ought to be tried.

As a leading water pump manufacturer in China, we understand the importance of addressing this problem effectively. Our company is committed to developing innovative solutions for airlock prevention. We are actively researching and incorporating new technologies. Aim to minimize the risk of airlocks and improve overall pump efficiency and reliability. Contact us today to learn more about our high-quality water pumps designed for optimal performance and minimal maintenance.

Don’t let airlocks disrupt your water supply. Our expert team also can provide tailored solutions and support to address your specific needs and help you prevent airlock issues in the future.

airlocks in water pumps

Table of Contents

Understanding water pump airlocks

Identifying an airlocked water pump