On electricity side. Check wiring and your electricity provider setting. They limit your electrical flow in Spain and you may be say on 1.1 which is okay without air con but need to ask provider to push you up higher say to 1.3 so your apartment can cope with air con. If you dont you risk the box tripping when you turn on your kettle same time as air con. It will increase the monthly charge on electric bill. You will find the existing setting figure somewhere on your electricity bill
Also the wiring, I replaced a gas boiler with electric one. All done with no hassle. A few months later I smelt burning in the flat. The plumber had connected the boiler okay but the plug for boiler was also used with washing machine and when both on , the load melted the electric cable.. so I had to get electrician in to install separate leads to fuse box for them
Good luck
Austin