Just to add to this debate. I do think the information you receive in the U.K is abit misleading. I made all the relevant enquiries before I left the UK and was sent a load of paperwork ( E106    ) Indicating that my husband and I were fully paid up with our national insurance and would be entitled to approximately two years of free cover under Spanish system. However on trying to register at Gandesa surgery today I was told that this is for emergency cover only, so anything routine has to be paid for. I was told I would need to go to an office in Tortosa to regsiter for all the family, Servei Catala Salut, CL L a Salle, 8, Tortosa between 9am and 2pm, tel. 977448170. So persumably we will need to pay a monthly installment to receive health care.
I would advise anyone planning on coming out to Spain to consider getting expert advice if they are at all concerned as the Pension Service who gave me all the info on the 106 were somewhat misleading.
Anyway I will be going to Tortosa next week to sign on so if anyone needs to know how this went just ask! I will be taking passports for all the family, NIE's, padronamiento certificates, bank book and the 106 forms that the Pensions authority gave me.