Why's my BMW 5 Series heater blower not working?

There are a few reasons why the heater blower in Your BMW 5 Series may not be working. These include clogged or faulty heating controls, dysfunctional thermostat, water leak, heater core issues, and not enough coolant. All of these issues can affect the heater blower. However, the blower might just need to be replaced because it's old, worn or damaged. When this part fails, You will usually feel a bit of warm or cool air from the vents, but there will be MINImal air pressure, regardless of fan speed and temperature. You may notice a grinding or rattling noise from the floorboard on the passenger side of the cabin when the heater or air conditioning is switched on. The average cost to replace the blower motor in this vehicle is $890 to $1,020. Labor makes up $500 to $640 of that total.