So, I had my bi monthly poke out of the drain as its been very wet/windy and I am not far from a whole row of silver birch trees. You know the ones. 75, killers with hundreds of spicky tiny seed pods. And yes, drain was running.... just, so managed to push through quite a clump of debris. First time I have had that much. So very pleased I did my Plems today !! Without the club I would never have known and for sure, by now my ECU would have been gurging away to itself. Thanks