As ed-o suggested,it is for Littlewoods to sort out, as per the Sales of Goods Act, but usually it is much quicker to contact the manufacturer in cases like Hoover. I think that you will find that they have local agencies who cover their warranty work,and it is a case of taking it in to them for repair. If its a washing machine then the service agent will call at your registered address . Doubt if you have grounds for a refund,unless the machine is a couple of weeks old. Less than 12 months would suggest a well used machine, especially if its a carpet cleaner, which I imagine that's what you are suggesting.
Funny that you should mention Hoover.I was in my local Littlewoods/Index store the other day, and a man was having a right barny with the store manager. He wanted a full cash refund under the 16 days return policy [which the stores terms and conditions do not allow on cleaners]. Threats of Trading Standards were made, but the stores manager was having none of it, especially as the cleaner looked well and truly tried and tested.Manager plugged the cleaner into the mains and tried it out, and no problems showed up, in fact it cleaned the store carpet very well.Eventually the customer left the cleaner on the counter and walked out of the store.Whether he returned, I wouldn't know.