How to Fix an Airlock in Pipes

Overview

An airlock in pipes can stop water flow. This guide covers clearing airlocks from the system.

Step-by-Step Fix

1. Start by turning on both the hot and cold water taps to their fullest extent, particularly those that are affected by the airlock. Listen carefully for any gurgling sounds or observe if a trickle of water begins to flow, as this might dislodge a minor airlock.
2. If the first method doesn't work, connect a robust hosepipe between the hot and cold spouts of the affected tap or basin, ensuring a tight seal with hose clips if necessary. Fully open both taps to allow water to flow from the higher-pressure cold side into the hot side, pushing the airlock back towards the cistern or boiler.
3. Once the hosepipe is securely connected and both taps are open, turn on the hot tap to its maximum. This creates a pressure differential that should force the trapped air out of the hot water pipe and back into the cold water system or tank.
4. After attempting to dislodge the airlock, check your boiler's pressure gauge, typically found on the front panel, and confirm it's within the manufacturer's recommended range (usually between 1.0 and 1.5 bar). If the pressure is too low, repressurise your boiler using the filling loop as per its instructions to restore adequate system pressure.
5. Finally, methodically bleed any radiators in your home, starting with the one furthest from the boiler and working your way back. Use a radiator key to slowly open the bleed valve on each radiator until water starts to emerge, indicating that any remaining trapped air has been released.

Common Symptoms & Diagnostic Resolutions

Review the common error codes and operating symptoms below to quickly identify the root cause of the fault before ordering replacement parts.

Frequently Asked Questions