Gas Fireplace Won't Stay Lit

[birdman579]

Hi,

I have a Heatilator GNBC33 NAT gas fireplace that was installed in my condo when it was built in 1997. After turning the fireplace on, it will only stay lit for a few minutes and they go out. The pilot re-lights just fine and will stay on forever. I don't start having problems until the fireplace is turned on. I can see a red colored piece of metal when the pilot is lit. I assume this is a sensor that keeps the gas flowing. When I turn on the fireplace, the flames near the sensor no longer flow directly over it and cannot keep the sensor red hot. Shortly after it cools down, the gas is shut off. I tried cleaning with compressed air and that worked for a month or so. Can anyone help me figure out why the flame pattern has changed? There is no signs of dust or dirt clogging anything. Is there a rear panel I need to remove? Thanks for any help you can provide!

[SeattlePioneer]

The pilot burner needs to be disassembled and the pilot burner and pilot orifice cleaned.