Assuming that you are in the UK, it is very simple. Tell the RETAILER (Becuase that is the party that your contract is with - not Hotpoint.) htta if they do not get their act together, you will 'Reject the the machine as 'not of mechantable quality' (In that it doesn't drain) under the Sale of Goods Acts.
Having said: 'I reject this machine' to the Retailer you are then entitled to a full refund, replacement or repair - ITS YOUR CHOICE - not the retailer's. Finally as this has occured withing six months of delivery it is up to the retailer to prove that the goods are of mechantable quality not you to prove that they are faulty.
Terry
March 2006