A rattling sound in the filter is usually the impeller. Either it is not installed properly or could be damaged. The impeller is located inside the motor head but can be removed. There is an impeller retainer that is on the underside of the motor head. This will come off in order for you to access your impeller. It needs to be removed and rinsed. This is to ensure that there is nothing impeding it from spinning properly. While out, you will also want to look it over to make sure it is not damaged. When reinstalling I suggest using the following steps:
1. Make sure all parts of the impeller are accounted for:
a. 1 white bar
b. 1 magnetic body
c. 2 rubber end caps (one can get stuck inside the housing of the motor head)
2. Attach one of the end caps to the white bar. You will want the white bar separated from the magnetic body.
3. Insert the white bar into the housing on the motor head, end cap first. Be sure you are in a well-lit area so you can see into the housing. There is a small hole that that end cap will fit into.
4. Thread the magnetic body over the white bar that is already installed.
5. Place second cap onto the exposed end of the white bar.
6. Align the impeller retainer. There is a small hole that the end cap will fit here also. The locking pegs should be just outside of the lip they will lock under.
7. Push the retainer into place. Do not turn it yet. You want to make sure that it is in fully before turning and locking in place.
At this point, you can plug the motor in for a moment to ensure the impeller is spinning. This is only a test. It will still be a little noisy at first but should quite down to a steady rhythm. Understand that it will not be this loud once water starts going through the motor. If this does not work, then contact us!