Air Locks

Advice on Getting Rid of Airlocks

Following a disruption to Water Supply some households may get airlocks in their internal plumbing system. The airlock is generally in the hot water system and most likely the result of faulty internal plumbing.

This is what to do if you get an air lock:-

Firstly make sure all hot taps in the house are in the closed position.

Then either proceed with either Option 1 or Option 2. The Final Step applies regardless of whether you use Option 1 or 2.


If the hot and cold taps in the kitchen are separate i.e.not combined in a mixer tap, the hot tap should be turned on. If there is an airlock, no water will come from the hot tap. A short length of hose should be used to connect the hot and cold taps in the kitchen only. Turning on the cold tap will result in the cold water being forced through the hot water system and this will force the air which is causing the airlock back into the water tank in the attic.

- OR -


If there is a mixer tap in the kitchen, the hot tap should be turned on. With a cloth in your hand (to help reduce water squirting out) block the mixer tap and turn on the cold water tap gently. This should force the cold water back through the hot water system, forcing the air into the water tank in the attic. Care should be exercised when doing this in case of accidental scalding with hot water.


Let this run for 1 – 2 minutes, then turn off the cold tap and let the hot tap run for 1 – 2 minutes to confirm that the air lock is cleared. If the air lock is not cleared, repeat the procedure one or two times more.

If this is not successful, contact a plumber and get them to correct the problem. In rare cases the cold water taps in wash hand basins or the bath may also be air locked. This procedure will also work for them, but is more difficult as a long length of hose is necessaryfrom the kitchen cold tap to the nearest wash hand basin or bath tap.

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