Hi there, my husband turned off water mains today and when he turned it back on we had no hot water. We managed to expel the air lock using a garden hose and the water downstairs is working but we can't get either the hot or cold to work in loft bathroom (ithasawater pump system). Any help would be greatly appreciated, Karen :)

First off, this isn't a air lock. A air lock only happens when you go to drain something and fail to vent it.
Why was the water shut off? Was something repaired or replaced? You have some trash in your lines either from dirt from the well or trash built up in the pipe walls.
What did hubby do? Whatever nit was he had to disturb dfgdesomething in the system.
Please post back with all the detail you can give me no matter how small. The more information I have 6the better I can help, Regards, Tom