Customer is concerned the thermostat is blank and not reading display. The thermostat is wiring correct terminal and no display on thermostat. Checked the batteries in the thermostat. The batteries are bad and needs to be replaced. Customer has approved for the batteries to be replaced. Replace 2 AA batteries and checked system operation. The display is working properly and unit is heating properly and running well. Test unit for cooling and unit is cooling properly. Thank you for choosing Total Air.