I have a Baxi Platinum 40HE High Efficiency Condensing Combi Boiler 15 months old, I had a leak from one of the plastic pipes in the radiator system so I drained the system ( repaired the leak ) and filled up/balanced the system and bled the radiators ( raidiator system now works fine. Tried to use the hot water - normally temp ranges from 35 - 60 degrees C, but since fixing the leak the temperature now starts to races away on the dial to over 90 and the flame shuts down and there is a banging noise from inside bolier - and the water pressure indicator needle fluctuates violently. Can anyone please offer me any assistance with my problem?