My old honywell thermostat model #T8411R 1028 (2) appears to have died. I purchased a newhoneywell thermostat model #RTH7500 series. It was working until I changed the temperature and it stopped working. It keeps making clicking sounds but is not coming back on. I am now waiting for an expensive cooling and heating service to come out tomorrow and meanwhile we are miserable in the house. Any suggestions for what I am doing wrong?

****COPIED to HVAC from E&L****

Have you checked breakers? Is the airhandler/furnace doing anything,any noises?is the condenser doing anything?

Back up and go over your wiring double check with instructions make sure its wired right

Check inside airhandler for (not knowing what kind of furnace you have) check circuit board for plug-in automotive type fuse see if its good