I know no one is going to bother, but I would love to see them try and defend that position in court. They can't bypass things like the sale of goods act, no matter what they say in their warranty. If the blade you had fitted was the wrong size or you had fitted it incorrectly, fair enough. But if you have replaced it properly with one of the correct spec, then this is nonsense. Of course you have to bear in mind that a warranty a a purely voluntary undertaking by the manufacturer, so they can refuse to repair it under the warranty for any reason they like. Interestingly you could argue that the warranty forms part of your contract with the seller. If this is the case then this could be seen as an unfair or unreasonable term in the contract. This was what the banks fell foul of over bank charges. Legislation says that it should be of merchantable quality, and last a reasonable time. If you formally rejected it on that basis, and demanded your money back, then in order to wriggle out of it they would essentially have to prove that your "modification" had caused the failure, or that your use of the machine was somehow unreasonable. What they count on of course is that when they point this bit of the warranty out 99.9% of customers are going to say oh bother I hadn't realised that, and that will be the end of it. There is an interesting comparison to be made with the motor industry. For years the only way any manufacturer would honour a warranty was if you had the car serviced at their dealerships, using their parts. It was the EU I believe that decided this was unreasonable, and ended it. So now you can have the car serviced by someone else, and using pattern parts, and that does not in and of itself invalidate the warranty. It is very depressing that in this day and age there are still so many companies whose default position is to deny a claim, and just stonewall the customer in the hope they will go away. Banks and insurance companies are masters of it.
