My york central unit inside thermostat red light is flashing twice. Unit isn't working

On the inside of the door/cover it should tell you what the flashing code is

If the red flash is coming from the thermostat, it is receiving an error message from either the furnace or the heat pump. Check the owner's manual and/or installation literature (if available) for further instructions.

Woops! My bad, it did say tstat ,my mama allways told me to pay closer attention