Here is an email I just received from Hydor:

Hello,

Hydor USA has asked their dealers and distributors to return any unsold Koralia 2/3 for a nonspecific inspection. There is no retail customer recall in effect at this time.

Please be advised that Hydor's 2-year warranty applies in full. Please feel free to return any Hydor item that is not performing properly.

Sincerely,

Hydor USA, Inc.