Hod do I re-attach the Drainage Hose on my Zanussi ?

Hi, The Drainage hose has become detached from the machine. Ove time, when it has been pulled out, we have trwisted it and now it has actually come off. There is a thread at the end so I think that over time, we have have just undid it.

Can anyone help and lt us know, how we can put it back on, is it a seal unit or can we do it ourselves?

Model is ZWD1270s

Thanks,
Peter