I had a new furnace installed (Trane XR95 - TUH1B080A9421A - single stage furnace) for my home. I find the fan quite loud and would like to lower the setting if possible (it has 4 settings). I look through the manual but am confused. Could any explain how I can achieve this?
Another common place with a schematic is on the back of the blower fan door. Most require that you open a box (2 screws?) with a wiring harness for the fan. 3 of the wires will likely terminate with just a twist on cap. But the 'real' one will be the one connected with a twist on cap to the fan motor.
If the schematic is on the door, note the color coding of wires and then swap, in your case, to a lower speed. Most high is usually for A/C.
If you lower the blower speed make sure you check the temperature rise across the heat exchanger or you may damage it. There should be a specification decal on the inside of the furnace adjacent to the gas valve. This will tell you the maximum temperature rise for your unit.
Before lowering your fan speed. Check the temp rise across the heat exchanger. if its high already. then lowering the blower speed may increase it above a safe level for the heat exchanger. And cause you lots of no heat problems. Or burn out your heat exchanger.