Thanks MunichTaxi, I might have to take the replacement option. I just enquired about the price of a recore for the heater core and it comes out to be the same prices as when I did the radiator !! - and that's with me doing the estimated 14hrs (if I new what I was doing) taking it out of the car in the first place.

I'm just working up the courage to start taking out the dash to get to the heater unit as I still don't know if it's the heater core or the connecting hoses.

Cheers,

Ysmael