1/12/22 Upon arrival found system's return vent making noise. The air was whistling off of it making the noise. Also noticed air conditioner and heat running at the same time. This is due to the customer installing and programming his thermostat incorrectly and putting the w wire in the wrong slot. I changed the wires and reprogrammed the thermostat. The customer was super happy and the delta when i left was 20 in cooling and 120 degrees when running the furnace