There are two official replacement parts listed for the fan blade in the 504.
99020166A Blade - 504-A, B
99020271A Blade 504-C,
What is the functional difference between the two parts? Is one quieter than the other?
Thank you for your question on the Broan model 504 fan blades. These two blades are not interchangeable, so you need to know your model number with the revision letter after it so you can be sure you order the correct part. The model number can be found up, inside the housing on a specification label. It will read 504-A, 504-B, or 504-C. Once you know the revision letter of your fan, you will be able to order the correct blade. For further questions, please contact Technical Support directly at 1-800-637-1453.
Date published: 2015-07-27