Impeller not pushing water up drain hose - Hoover washing machine?

hi,
my hoover front loader washing machine is not draining properly. I have opened the front filter and removed debris from this section. I am also pretty sure that the drain hose is clear as i can empty the machine by hand by emptying it into a bucket low down. the problem seems to be the impeller (spinning) part in the filter which it seems is not pumping/pushing the water out. When i spin the impeller, it sort of has resistence every revolution - is this normal? what other things can i try ? I'm not sure whether i am up to removing the drain hose completely as i saw there is a clamp holding it on. Is there anything else i can try before calling out a technician? THANKS!