how to permanently fix the EA error code and loud grinding noise?

I have the same problem reported here by many, where by my Scottish Gas boiler is making a very loud grinding noise which then inevitably leads to the EA code flashing and boiler stops working.
It is not cold enough to be a frozen condensation pipe so I've not looked into trying the 'kettle trick'.
I have tried the emptying of the small cup inside the boiler and allowing it to drain out. Which does fix the situation after a reset. But this fix only lasts for about 24 hrs and then it breaks again. I've done this 4 times now in last 5 days. It is a workaround for now, but I obviously cant keep doing this daily.
Does anyone know of anything else I can try before I give in and call out the experts?

Any advice would be greatly appreciated.
Thanks in advance.

Ben B
November 2015