Ok, please look at the link. Ok next question how do I use this to get water into my system ? do I turn the key then the nut , is so in which direction do I turn the key and nut. Thanks for your help.
http://www.worcester-bosch.co.uk/index.php?fuseaction=accessory.detail&con_id=125928&detail_id=6388
http://www.worcester-bosch.co.uk/index.php?fuseaction=accessory.detail&con_id=125928&detail_id=6388