i dont know much about what u mean. eco mode is the best economical mode for the hot water to be set at a constant rate. its not a setting. anyway here is a place where u can download the missing manual.
http://www.ultimatehandyman.org/PDF/Saunier-Duval/Saunier-Duval-Thema-Classic-F24e-Installation-manual-47-047-35.pdf
kash
January 2013