I have no hot water or heating. I have a Keston C40 boiler which is showing a low water pressure fault. A plumber has been to see the boiler and has diagnosed the problem as being low water pressure and air in the system. The radiators make a gurgling sound when the heating is switched on. A plumber has released air from all the radiator twice but this has not helped. All the radiators where de sledged last year so we thought that this year we would be problem free.