Led Televisions are rated to last around 10 years with 8 hours of TV watching per day.
But I only watch around 4 to 5 hours of TV per day and I find that at 5 years my TV doesn't even want to come on anymore and I have to buy a new one.
I've had my new Led TV now for 2 years after my last one died at 5 years so I expect another 3 years before needing to get a new LED TV.