I dont now wich voltage you have there in spain, 110V or more? Because, here in germany, we have 220V, so heating isnt the problem. Earlier machines had a 100° boilwash and finished it within 2 hours. the problem is the energylabel. It just shows the range fom A+++ to D, but not, as 5 years ago, the cleaningperformance. It just says "Hey, i save energy" but not "i save not that much energy, but clean your clothes twice as good as the other machine."
But , even through, there are some machines, which can save a lot of energy, but also have a Allergic-cycle which reaches the temp and sanatizes things as well. Like our Panasonic reaches 80-90° on the 90° setting, but if you press eco, it just reaches 55-60°. Our second machine, a A+++ machine to, reaches 95° straight away (its a AEG), but on eco 60°, it just reaches 44°.
On your LG:Try it ones without any clothing and check, if it reaches 90°. If not, phone LG and tell it to them and ask, if something can be done against it.