Air lock in pipework

Air lock in pipework

A tap which fails to supply water when opened might be airlocked.

Removing the air lock using housing hose

To overcome this, attach a length of hosepipe to the affected tap and connect the other end to a working direct feed tap. In most cases this might be the cold tap on the sink.

Open both taps to allow the pressure of the mains water to force the air back out of the pipes. Leave to act for several minutes, then pack up the air locked tap first.

It may be necessary to repeat this a few of times to release the lock and permit water to run properly.

When finished, undo the hose from the upper of the two taps, before releasing the lower and allowing the water within the hose to empty into the sink.

Air lock at quite one tap

If quite one tap appears to be airlocked, clear it from the lowest one.

With cold water pipes from the attic cistern, it’s getting to even be possible to blow out the airlock if the above method fails.

Push a length of hose into the outlet pipe within the tank. Open the faucet at the opposite end. Blow through the pipe to dislodge the lock.

Draining right down to remove an air lock

As a final resort method, drain the system down. close the water feed and open all the taps to empty the water.

Close all taps until they seem to be a few three quarters closed. Turn the water system back on.

Adjust all of them until a lightweight, even flow of water is achieved.

Now go around opening them one by one to the half-open position, starting with the lowest and dealing upwards.

Repeat at the three quarters open position. Once all air has been discharged, turn all taps off to some extent where there’s only a minimal flow.

Finally, close all of them before checking the operation of each successively.


Edinburgh Central Heating Services offer free estimates and range of skills. A 24-hour emergency plumbing service is also offered. For more information visit or telephone 0131 5102418