Wear on the impeller - When should I replace it?
There is no general answer to this question. As with a car tyre, the duration and intensity of use is decisive. Many customers use the impellers for several years without any noticeable change. Heavy use of the impeller results in a shorter service life. With a car, you know the wear and tear caused by heavy braking, mechanical damage and many kilometres driven.
The following factors apply to an impeller:
1. Running time in hours
2. Throttling of the flow rate (max. 50 %) and thus lower cooling capacity
3. Dry running during water change (see 2.)
4. Mechanical damage (e.g. by snails, improper installation after removal, ...)
5. Heavy soiling
As it is a wearing part, the impeller is not covered by the warranty. For a long service life, you need to clean it regularly. This will prevent increased running noises. The impeller housing, the impeller and the shaft can be cleaned with a suitable cleaning brush.
If it is necessary to replace the impeller due to wear, always replace the complete set, impeller with shaft and 2 rubber bearings. This is the only way to ensure proper functioning and smooth running. When removing the impeller and shaft, a rubber bearing often gets stuck at the bottom of the impeller housing and is very difficult to remove. JBL has developed its own special tool for this purpose, which is available from pet shops under the name "Pulling aid for impeller bearing". A useful cleaning brush for the impeller housing is also included in the tool.