vokera excell 80sp problems.

[ludders]

I currently have a vokera excel 80sp combi boiler.Just recently the boiler has started to bang and boil the water in the heat exchanger.The boiler is 7 years old.The safety stat is working and shutting down the burners.It does this both with the hot water tap and central heating.What also occurs is that the central heating pressure is affected when the hot water tap is turned on.Dropping the pressure down to 0.5 bar but returns to normal working pressure when the tap is turned off,Any ideas would be greatly appreciated.

 

[DP]

What is your normal working pressure?

 

[ludders]

normal working pressure is 1.5 bar.

 

[ChrisR]

Is the pump running - in other words do the rad pipes start to get hot? Or remove end screw and poke summat in.

 

[ludders]

the pump is running,radiators getting hot.Every thing seems to be working as normal apart from the banging and boiling.