I have read a lot of complains about bio-wheels stop runnin. When it's clogged or blocked or when water level isn't within range they stop working, otherwise... I guess some defective ones get into the market anyhow.
Have you tried contacting their customer service department? At least technology wise bio-wheel filters design seemed a good idea... Nevertheless I love AquaClear when it comes to HOBs despite its old-tech design.
Hope you take it easy and learn to "enjoy" setbacks like these ones (I'm not being sarcastic), we end up learning a lot, in the long run at least, and if you find a solution, sharing it will help others too. Part of the game I guess.
Pepe
Santo Domingo