How do i get rid of an air lock in a combi boiler?

I have never heard of an air lock in a Combi Boiler, because of the high pump pressure circulating the water. However, there should be 2 air vents on your boiler. One is on top of the pump, and the other one is a Automatic air vent on top of the boiler. This one does get rid of any air ping through the boiler automatically. They can however sometimes get a bit of grit in them so just check that it is working by switching the boiler off for 10 minutes, then unscrew the cap very slowly and see if any air hisses out. Do not remove completely!!