After thinking it was a frozen condensate pipe that was upsetting the worcester, the problem has returned, The wife turned the C/H on and heard a strange noise then after a couple of minutes a small drip of water appeared for a minute at the back right of the boiler then stopped..... but water trickling can still be heard "inside" the boiler. I took the cover off thinking it was the condensate again but that is clear and unblocked. There is also signs of water around the base of the inside of boiler as per pics.....Any ideas chaps......the other info i have is that the pressure of the sealed system is approaching 2. I should say that it is a pumped H/W and sealed C/H system with a thre way motrised valve, Im afraid i cant remeber which plan it is called......However the system is still working bith C/H and H/W