Replacing old thermostat with new digital

Incorrect low voltage wiring, or if the wiring is old, most likely a break in the insulation of the wiring creating a short.
First thing, check the wiring diagram to see that all wire colors are attached where they should be at the thermostat.
Then look at the wiring diagram at the air handler and verify the control wires are on the proper terminals.

Did you try E too aux and x1 to c?

digital thermostats often use batteries some installers do not connect the common wire which will cause the thermostat to go blank when the batteries run down. unsnap the face of the thermostat off and replace the batteries

If you did not turn off power to the air handler the transformer shorted out.
Otherwise,red goes to r/rc,green goes to G,yellow goes to Y,white goes to W/W1,orange goes to O,black and or blue goes to Common.(C)

From Honeywell : "If your old thermostat had Six or more wires, the replacement you have is Wrong!"

Because the outdoor unit works in cooling, it sounds as though the contactor and other components outside are working correctly. The problem sounds as though it might be somewhere in your thermostat. Has the thermostat been replaced recently? If so, make sure it was wired correctly. If not, check all of the connections and contact points in your thermostat. In order for your outdoor unit to run, you must have 24vac at your "C" Common and "Y" connections. You must have this in COOL mode. Now it has to be determined why you don't have it in HEAT mode. Definitely a thermostat issue.

Hope this helps and good luck! :-)

I can give you a start, For heat only, R terminal on furnace to Red wire to R or RH terminal on thermostat. W terminal to White wire to W terminal on thermostat. G terminal to Green wire to G terminal on thermostat. This will get you heat but not air conditioning.

Depending on the size of your Electric heat you can use one set of wires because your unit does not run with the heat like the heat pump. The large set of wires going to the electric heat should be used. You may have to jumper a new set to the contactor. On Goodman unit come in L1 and L2 jumper to contactor. Very simple good luck. Rus

double check your t-stat wiring your not getting 24volts to the contact at the cond. unit outside

new unit and old thermostat/wire? thermostat could be bad or bad thermostat wires. try putting in new of anything old. do this wiring practice with the terminals being the letters.

r- red (24 volts)
w- white ( heat)
y- yellow (cooling)
g- green (fan)