The Usual fix for this problem:
Fix a length of hose onto the tap and run and connect the other end of the hose to a known working tap. This is normally the cold tap at the kitchen sink. Open up both of the taps to let the pressure of the mains force the air out of the pipework. Let it run for a few minutes and then turn off at the air locked tap. Brockley Plumbers have the necessary skills required to cure an airlock. You may need to do this a few times to get rid the air and let the water flow correctly. Once done, uncouple the hose from the higher of the two taps, and then, the lower letting the water in the hose drain down the sink.

Air-lock At More Than One Tap:
If more than one tap is air locked, you should always work from the lowest tap first. Using cold water pipes from the cistern in the loft, it may also be possible to blow out the airlock if the above method does not work. Put a length of hose into the outlet pipe in the cylinder. Open up the tap at the other end, blowing through the pipework, dislodging the airlock.

Drain Down To Remove An Air-lock:
A final method is to drain the whole system down. Isolate the water feed and open all taps to drain the water away. Close the taps to about a 3/4. Turn the water supply back on. Adjust them all until a gentle even flow of water is achieved. Now go round opening them one by one to the half-open position, starting with the lowest and working upwards. Repeat at the three quarters open position. Once all air has been discharged, turn all taps off to a point where there is only a minimal flow. ABrockley Plumber will fully guarantee the work.