When I arrived, the home was at 57°. When I turned the furnace on the blower came on at full speed and there was a call for the AC to run instead of the heat. I double checked wiring and wiring past inspection. I then went through the settings on the thermostat and the settings were incorrect. I fixed the settings on the thermostat and furnace kicked on as it should. I double checked temperatures and filter. Furnace is operating as it showed at departure. I let customer know what had happened. I did recommend having a search protector put on the house or on the furnace and AC to protect the system. I also offered our club membership for continual maintenance which also helps keep the warranties active for the system. When we come back out to check the AC refrigerant pressures, customer would like to re-look at the membership at that time.