if its the same as the 30 cdi you need a t shaped white key, it should have been left in the white pannel at the bottom of the boiler which pulls out, but not allways easily, then with this pannel removed look underneath to find the charging link. insert the key at 45 degrees and open the white nut untill up to 1 bar then cllose and remove key, a bit of washing up liquid on the rubber of the key helps it , do i make it sound easy? its a pain, why they continue with this troublesome and prone to problem method of filling i just dont know
john
March 2010