Hmm... haven't measured the voltage on the wiper 
Will do tomorrow. (How come i fail at these simple tasks but manage to hook a NTC to the arduino and calculate to be accurate to 0,01 Degree Celsius? (Off Topic))
And since i cannot go below the reference... Is there a way for this? For a Led to turn on when Voltage hits and drops below 2.5V?
Example: A second circuit to be given the signal from the 431 that the Voltage is at 2.5 and below? Like a FET and a coincell hooked to a LED? (Bad idea? It's getting late xD shouldn't think this much before bed)
EDIT:
Solved it!
a NPN and a Zener plus two 100 Ohm Resistors. Works like a charm ^^