Candy GO482 Drain Fault

Hi,
I have an intermittent drainage problem with my Candy GO482 2/80 machine which has recently been getting worse to the point where its no longer usable. The machine stops when it gets to the drain part of the cycle and displays the error code for not draining in the allowable time (3 flashes). The problem seems to be worse on colder and shorter washes although it may be my imagination, it now seems to do it almost all of the time. I’ve read all the help pages as well as a lot of googling and I’ve tried the following but still with no luck – any help would be appreciated!

1 – checked all hoses for blockages, all clear – drain it flows into is clear too.
2 – blown down pressure switch tube, seems ok
3 – replaced pressure switch for new component
4 – fully removed pump and all drainage pipes for close inspection – all clear (confident!)
5 – measured resistance across pump connectors – 170ohms – after googling seems to be what it should be, impeller seems to be ok

Could the pump still be faulty? should I replace it and see or am I wasting more time and money! I need to get this fixed quickly else I’ll be forced into getting a new one by the missus!!!

Any help would be massively appreciated since I’ve run out of ideas!

Thanks,
Sam