Had the same problem. The pump had run dry and then continued dry wrecking the rubber impeller. Open the pump head, replace the impeller using soap the lubricate the housing then remount making very sure that all the hose connections on the suction side are airtight. Use sealant if necessary. I fitted filter to the suction inlet to avoid crud from the bilge getting into the pump and causing the problem all over again. Success.
The membership association for owners of Dufour Yachts