What Causes Airlocks in Pipes and How to Fix Them

If you’ve turned on a tap and heard a gurgle—or worse, no water came out at all—you may be dealing with an airlock. Airlocks in pipes are a common cause of poor water flow, spluttering taps, and malfunctioning heating systems. While frustrating, they’re usually fixable with a few simple steps.

At Pleasant Plumbers, we help homeowners and property managers across London resolve airlocks quickly and efficiently. Here’s everything you need to know about what causes them, how to prevent them, and the safest way to fix them.

An airlock happens when a bubble of air becomes trapped in your plumbing system—usually in your hot water or central heating pipework. Because water can’t flow past air easily, it causes blockages, low pressure, and inconsistent supply.

• System Draining or Refilling: After repairs or maintenance, air can get trapped during the refill process.
• Boiler Issues: Faulty valves or low pressure can allow air into the heating system.
• Poor Pipework Design: Long vertical pipe runs without air vents can increase the risk of airlocks.
• Leaks: Small leaks draw air into the system, especially in sealed central heating systems.
• High Points in Plumbing: Air naturally rises—if pipes dip and rise, air can become trapped in the high sections.

For Hot Water Taps:

Method 1: The Hosepipe Trick

1. Connect a hose between a working cold tap and the hot tap with no flow.
2. Turn on the hot tap.
3. Turn on the cold tap to push water (and air) back through the hot pipe.
4. Run both taps for 1–2 minutes.

Method 2: Bleeding Radiators
If the airlock is in your heating system, try bleeding your radiators—start with the one furthest from the boiler. This often clears trapped air in the system.

If your taps are still not running or your radiators remain cold even after bleeding, the airlock could be deep in the system. At this point, it’s best to call a qualified plumber in London like Pleasant Plumbers.

We’ll trace the problem, flush out airlocks safely, and check your system for faults like pump failures or expansion vessel issues.

• Ensure all repairs are done by a Gas Safe heating engineer in London
• Top up boilers carefully and always bleed radiators after
• Insulate pipework to avoid temperature-related expansion and contraction
• Book annual system servicing to catch small issues early

Don’t put up with spluttering taps or uneven heating. Contact Pleasant Plumbers for fast, expert plumbing support across London.

📲 Call or WhatsApp 0800 046 1000
📧 Email [email protected]
🌐 Visit pleasantplumbers.com

Searching 'Plumber Near Me?' Plumber London or Commercial Plumber London? We operate all across London! If you need a trusted plumber in London then get in touch with us today on 0800 046 1000 or email us on [email protected]
Pleasant Plumbers – Where Trust Flows Like Water.