Originally Posted by gsr
Its' never too early to order one to have a spare around. Otherwise, just replace it when the picture gets noticeably dim or the bulb blows, but I wouldn't expect to need to replace it until at least ~1500 hours or so of use.
Lets think about this more.
1. 3 hours a day, 365 days a year is 1095 hours of use in one year and that is most likely a little low for the average. Ray's TV is showing well under a year's use.
2. While the bell curve for lamp life is very broad which means average is not that helpful, the average life of a lamp (THEY ARE LAMPS, NOT BLUBS) is well over 1500 hours and 5000 is not unusal. I have heard of a lot of lamps that last over 10,000 hours.
3. Replacement lamps may or may not have a warranty but if they do, it is based on time from the date of purchase NOT INSTALLATION. Often warranties for replacement lamps are 90 days to one year. So if you purchase a lamp now and your original lamp lasts 5000 hours you will have the replacement lamp on the shelf for several years. After that 5000 point you install that replacement lamp and it last only 3 months (it can happen, anything can fail). Now you have no warranty for that replacement lamp.
4. If you are only at 664 hours, you have a better than even chance it will last much longer. Since most lamps are delievered in less than a week, I personally would wait longer before getting a new lamp.