You state that you bought the item 'about 6 months ago'. It's important as to whether it was more or less than 6 months.
When you first buy an item you've got a right to receive a full refund, if it's faulty, up until the point when you've legally 'accepted' it. The duration of the pre-acceptance period isn't defined in law but generally it just gives you enough time to check that everything's working properly and to complain if it isn't. You seem to be well outside that period.
Thereafter, for a period of 6 years after purchase, the retailer must repair or replace the item if a problem arises due to an 'inherent fault'. That means a fault which was present at the time of purchase, such as the use of poor quality materials or poor workmanship. For the first 6 months after purchase there's an automatic assumption (unless there's clear evidence to the contrary) that any problem must be due to an inherent fault. For the remainder of the 6 year period it's up to the purchaser to show that the problem has arisen from an inherent fault.
Assuming that you can establish that the problem with your purchase is due to an inherent fault (either because it occurred within 6 months of purchase, or otherwise), the retailer is obliged to repair or replace the item. You can state which of these options you prefer but the retailer can substitute the alternative option upon the grounds of economic viability.
All of the above refers to your statutory rights with the retailer. As Bozie69 points out, it's likely that the fridge/freezer was supplied with a manufacturer's guarantee. However such a guarantee is a 'gift' from the manufacturer and is not directly covered by any legislation. The guarantee can cover as little or as much as the manufacturer decides.
Chris