Mine (I think it's a Siemens, but most of them are made in the same factory and come out with different labels on) also takes 3 hrs for the economic programme. However, the German equivalent of "Which" tested them and said that the 60° economic wash only heated the water to 27° - 34° at most. That's colder than the water you shower with! So I NEVER press the "eco" button now, although I'm still not convinced that, even then, the water is heating to the 60° or 90° it says on the controls.
The 15-minute programme probably doesn't kill all germs, but I would only be worried about that for underpants and tea towels, which I wouldn't wash at less than 60° anyway. Same applies to all the other programmes. I mainly use the wool wash for outer clothes, with a wool-washing agent, pre-treating stains with a spray-on stain remover. It really doesn't matter if jeans and tee shirts aren't free of germs, as long as they are clean and smell fresh, does it?