I have 3 wires coming out of my wall a red white and blue I am not sure wich wire goes where on my new thermostat the codes are w y g rh/rc (jumpered but I disconnected does that need to be reconnected?) I don't have central air or a fan that will run all the time inside my heating unit there is only the blue and white wires hooked up where it says thermostat what is the correct way to wire the new digital thermostat?

Did you happen to notice where the wires went on the old thermostat? Noting that would have been helpful. If the traditional wire codes haven't been followed, the best thing you can do is open up the furnace and see where each wire goes... then you won't make any mistakes.

If blue and white were the only wires connected before for heat, then I would connect White to W(heat), and blue to rh/rc.
You could use a multimeter/continuity tester to confirm switching when set to heat, and temp set low.