Changing exhaust fan blades is one of two options you have when faced with a noisy fan, a broken or damaged fan blade, or one that is not working. It's unusual for a fan blade to break, but it can happen. Homeowners often assume a loose or rattling fan blade is causing the noise in their bathroom or house exhaust fans. Chances are better that the noise is the motor, not the fan blade. It's rarely a good option unless you have the replacement blades already. The cost of purchasing a replacement blade is about the same as replacing the entire fan. So, most homeowners or maintenance people tend to simply replace the unit.
Replacing an Exhaust Fan Blade
Unlike ceiling fans, where each blade attaches to the motor individually, exhaust fan blades come as one unit. If one fin is damaged, the entire unit must be replaced. If you would still prefer to replace the blade rather than the unit, make sure to take the old blade with you, or to copy down the name, serial number and other identifying numbers and letters for your fan. Blades vary from unit to unit and getting the right blade replacement ensures you won't have further troubles once you install your replacement.