Halide bulb burning out?

I have a 5-6 year old Coralife light fixture that has been retrofitted with LED's and has 3 Phoenix 250 W double ended halide bulbs. This evening, one of the bulbs went out and then came back on several minutes later. I thought these bulbs never went out, only needed to be replaced after a certain number of hours. Is my understanding incorrect and I just need to now replace the bulbs?

 

Switch your MH bulbs around. That will help pin point if the problem is your bulb or your ballast. If the problem follows the bulb, then its the bulb. If the problem stays with the one socket, then likely you need to replace the ballast.

 

How old are the bulbs?
Edit: If you're referring to the MH, I try to change mine out every 6-9 months.

 

That old tar ballast could be contributing to this issue too. If you replace it with a new electronic one such as a Lumatek, you could extend the life of the bulbs - or at least, that is, keep them performing well.

 

Any chance the ballast got too hot and you witnessed it go into thermal protection?

 

The bulbs should burn forever as far as I know(although they will eventually turn yellow color) Sounds like something other then the bulb..