Most of the submersible pumps available in the market are up to an extent maintenance free. But few things are to be noted for the efficient use of these pumps.
1. Do not attempt to modify this unit in any way, Always get in touch with the manufacturer of the pump or the supplier.
2. Always cut off the power supply and ground the pump properly.
3. take off the impeller cover - clean and replace the same.
4. Remove the impeller and impeller shaft - - clean and replace the same.
5. Inspect and clean the impeller casing and replace the impeller and impeller cover
6. Inspect the O-rings and clips for any damage.