Air lock in hot water system (low hot water pressure)

[addey]

We were away last weekend so I turned off the hot water. Got back Sunday evening to discover that the boiler had lost pressure and the hot water was coming out of the taps at a trickle. I re-pressurized the boiler and it is all working fine, however the hot water pressure is still woeful. Bizarrely it seemed to sort itself out Sunday evening as I managed to run a bath but the whole rest of the time it is barely a trickle. I assume there is an airlock somewhere but I've no idea how to get rid of it?

Its a sealed system (megaflo type cylinder, no tank in the loft). I know the boiler is working OK as our bathroom towel rails are on the hot water circuit and they are getting hot as normal.

Anyone got any suggestions how to get rid of the air lock? Should there be a bleed point somewhere near the cylinder?

I've got someone booked to come out next Tuesday but would obviously like to wash before then