Turned on AC for first time last Monday. Worked perfectly. Next day I noticed AC was not working. Checked thermostat and a blinking light on LUX 1500E constantly blinking. Changed batteries in thermostat. No change. Hit reset button on thermostat and reprogrammed. No change. Turned on heat and see if furnace turned on and it did not. Gas heat with AC unit (new compressor unit 2 years ago).

Any suggestions?