Truma Outdoor Shower-Help Please!

wandering1

I dont know ifthere is anyone out there who can give me a little help and advice please. I have a 2013 Lunar Cosmos which has a Truma water system. I am currently in Spain and ordered an outdoor shower attachment from the UK. It has been delivered minus
any instructions! Yes I understand how to attach the actual shower bit but I have a blue plastic bit left over?!!! After fitting the shower head no water comes from it! Am I being thick?! Surely this blue bit of plastic must be there for something?!! I have
e mailed the supplier several times and not had a response. I cant be the only person thinking that if it ever worked it could be really useful! Thanks for your help Jean