I know I should be paying you for call out but lets try and remember the spirit of the forum (vodka?) I have a very antiquated system which currently has an airlock (I think) which means the cylinder is not getting hot. I can hear where the lock is and it's in a pipe which runs up to a 90 degree bend with two 90 degree spurs off. The two spurs get hot but the heat does not get as far as the bend, I can hear it bubbling just below the 90 degree bend. Help!

My boyfriends jus qualified

My uncles a qualified plumber with his own business. Corgi registered as well.
Can do lots of other jobs too...

Sounds like it's airlocked on the Primary side of the cylinder. These are the pipes which come from the boiler carrying the hot water which in turn goes through a coil in the cylinder to heat up the Secondary water ie. the water which comes out of the taps. ( I'll try to keep it simple!). The airlock is probably in the Flow ( upper pipe ) which enters the cylinder about 1/2 way up. Where the pipe joins the cylinder should be a large brass nut, which if you slacken it off should release the air before water appears, when it should be retightened. This is only a temporary measure, as there is obviously a problem, which could be caused by various things. It would also be a good idea to check the header tank in the loft( the small one) to make sure there is water in it. It is possible that there is a small leak and if the tank is not topping the system up, then that would also cause the problem you now have. Hope this all makes sense.

useful to know that there are at least 2 plumbers out there one green and one experienced now none of us need to worry! :)

Thanks for your reply Magneteer, I'm sure it will make some sense when I can stand in front of the system and see the pipes. As it happens I turned up the speed of the pump last night and also turned off the radiators (furthest from boiler first) and left one closest to boiler still on left it running and went out. When I came back a miracle had happened I had hot water and no gurgling from the pipes. Irealise this is only a temporary fix but at least I can now wash up ..... oh happy day.

Thanks to the three people who replied