Your thermistor isn't reading properly. Make sure that all your connections at tight and that all the crimps are good. you can take a small flat head screwdriver and Try pushing on the wires in the back of your connectors until they read something like 25-30c. Do NOT turn you heaters on until the thermistors read something.
SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.