hotpoint ultima fdw80 top impeller not rotating?

As Phil says its the top spray arm seal, a clue is black rubber flakes on the pipe stubs at the back of the top basket ie the ones that connect into the failed seal. Easilly orderable from hotpoints parts dept.
TOP SPRAY ARM NUT WITH SEAL (ROHS) FDW80P
TOP SPRAY ARM NUT WITH SEAL (ROHS)
C00144315
https://parts.hotpointservice.co.uk/indb2c/catalog/setCurrentItem/(isQuery=yes&query=*%24%24FDW80P%24&layout=6_1_62_63_5_2&uiarea=2&ctype=areaDetails&next=seeItem&carea=%24ROOT&citem=00000046520000000153)/.do

John
March 2011

I had the same problem recently, there is a rubber seal on the nut at the rear of the machine which the top wash arm assembly pushes into, this seal split so there was insufficient pressure to operate the top arm, the seal is part of the nut and easily replaced.

Phil
May 2007