I thought I had this problem solved.....
New Sherwood pump with one piece bronze casting
Global run-dry impeller...
The global impeller has started to shred itself and we had code 7 after 173 hours.
Admittedly that's nearly twice what we were getting from the Onan pump and impeller, but its still not very good !
SV Elyse SM437, currently Taina Marina, Papeete