Hello my friends - I hope someone can help me.

My problem - There is no cold water coming from my shower. There is hot water, but no cold. There is cold water coming from all the other taps in the house. The shower is a 'power' shower which has both cold + hot pipes feeding into the shower box.

Yesterday the water was cut off (The whole village had no water) - not sure whether this has anything to do with it?

A friend has mentioned that it could be a airlock?. Is this the problem?. and if so how do I solve it?

Thanks for your time and help.