If air becomes trapped in your plumbing system, it can cause taps to splutter or fail completely. To force the air out, you can use mains water pressure.
Attach a length of hosepipe to the affected tap, with the other end attached to any tap on a direct system (kitchen cold water tap for example). Open both taps for a while, then try the airlocked tap again. If it is still failing, repeat for a longer period. Don't forget to drain the hose before moving it once you are finished...