Hotpoint sdk80 fault

This sdk80 is second hand but worked ok. It started to show various faults and appeared to boil the water after the drain pipe was feed directly into a drain rather than into a standpipe. Would not having the recommended head on the drain outlet cause pump or heater problems? After raising the drain pipe to the correct height does not fix the problem so I suspect that the damage is done. Taking off the right hand side it looks as if the water is not circulating. Any guidance would be appreciated. Thanks…..Kevin