Air lock in Water Systems

 

An air lock in a water system happens when air gets trapped in the pipes, preventing water from flowing through normally. In a well-functioning system, water should flow smoothly through the pipes without interruption. However, when air is introduced into the system, it can form pockets that act like a barrier, stopping or severely limiting the water's flow. This problem can arise in plumbing systems for homes, heating systems, or even industrial water systems.

How Air Lock Forms

Air can enter a water system in various ways, including:

• Plumbing repairs: When pipes are drained for repairs or maintenance, air enters the system. Once the repairs are done, air pockets may remain in the pipes.
• Water supply interruption: If there is a disruption in the water supply, air may enter the pipes as water is drained out, especially in systems where water pressure suddenly drops or fluctuates.
• Poor system design: In some cases, the design of the plumbing system itself may lead to air being trapped, particularly if there are dips or high points in the pipes that allow air to accumulate.
• Filling a system too quickly: When a water system is filled too rapidly, air may become trapped in certain sections. 
  
  
  

Common Effects of Air Locks

• Inconsistent water pressure: The trapped air interferes with the steady flow of water, causing the pressure to fluctuate. You might notice that the water sputters or comes out of the tap in bursts rather than a smooth flow.
• Complete stoppage: In more severe cases, the trapped air can block the pipe completely, cutting off water to a certain faucet or system altogether.
• Gurgling or hissing noises: As water struggles to move past the air pocket, it creates noises in the pipes that can sound like gurgling or hissing.  

How to Detect an Air Lock

1. Check for Low or No Flow: If water is flowing weakly or not at all from certain taps, especially in a hot water system or at high points in the house, an air lock might be the issue.
2. Listen for Unusual Sounds: Air locks often produce sputtering or gurgling sounds as water tries to pass through.
3. Compare Cold and Hot Water Flow: Air locks are often more common in hot water systems, so comparing the pressure of the cold water versus the hot water at different taps can help detect an air lock. 
   
   
   

Ways to Fix an Air Lock

1. Bleeding the System:

   • This involves turning on all the faucets in the system to let the water flow freely. This can help the air escape from the highest points in the system where it may have collected.
   • Start with the faucet on the lowest floor and work your way up to the highest one. Keep the taps open for a few minutes to see if the pressure stabilizes.

2. Creating a Flow Between Hot and Cold Taps (For Hot Water Air Locks):

   • This method works in systems where air is trapped in the hot water line.
   • Turn on both the hot and cold taps at a sink, and then block the spout with your hand or a cloth. This forces the water from the cold tap (which usually has higher pressure) to flow backward into the hot tap, pushing the air lock out of the system.

3. Using a Hose Pipe:

   • Another effective technique involves attaching a hosepipe between a working tap (with good water pressure) and the tap with the air lock. The idea is to use the pressure from the working tap to push the air out of the affected pipe.
   • Run the water through the hose for a few minutes. The higher pressure from the unaffected tap should force the airlock to clear.

4. Automatic Air Release Valves:

   • Some plumbing systems have built-in air release valves, particularly in heating systems. These valves automatically expel air from the system, preventing air locks.
   • In some cases, these valves can be opened manually to release air that has accumulated.

5. Specialized Tools and Equipment: Plumbers may use specialized devices such as pumps or plungers designed for clearing air locks from water systems if basic methods don’t work. 

Preventing Air Locks in the Future

• Gradual Filling: When refilling a water system, do so slowly to minimize the amount of air that gets trapped.
• Regular Maintenance: Regularly inspecting and maintaining the plumbing system can help prevent the formation of air locks.
• Proper Ventilation: Ensure the system is properly vented so that air can escape as the system operates.
• Use of Expansion Tanks: In some water heating systems, expansion tanks can be used to manage pressure changes and prevent air from getting trapped. 

Situations Where Air Locks Occur Frequently

1. Boiler or Central Heating Systems: Air locks are common in hot water systems like central heating because they often involve complex pipe layouts with many high and low points where air can get trapped.
2. Domestic Plumbing: After plumbing repairs, air locks often occur in household water systems, especially in areas like upper-floor bathrooms or kitchens, where pipes are higher and air can rise and settle.

If the air lock cannot be resolved with simple methods, a plumber might be required to investigate deeper problems or use more advanced techniques to clear the blockage.