Manufacturers usually provide an additional warranty, at their own discretion, they do not have to provide this. Consumer law usually states that within the first six months, the onus is on the retailer to prove the item was of satisfactory quality and fit for the purpose. After the first six months the customer would have to provide evidence that the item was not fit for the purpose or of satisfactory quality.
In the case of goods like televisions, retailers usually advice the customer to perhaps contact the manufacturer for repairs and service, as this may be the quickest way in obtaining replacements or repairs. But only do this with the agreed approval of the retailer. The customer is not obliged to take this route of action. If Currys have suggested that they are not responsible, then I would suggest that contact with Consumer Direct click here would be advisable before proceeding further.