The pilot assembly on a propane fireplace is a low-maintenance component under normal conditions, and if you keep a very tidy home, you may never need to go out of your way to clean it. However, dust and dirt can clog the small opening in the pilot assembly over time, and this may cause the pilot to fire improperly or to not fire at all. Fortunately, pilot cleaning is often fast and easy to undertake.
Turn off the fireplace if it is on and shut off the main gas valve. If it has been running recently, wait until all components are completely cool to the touch.
Use a flashlight to look into the tube where the pilot flame comes out. You'll see a smaller tube with a tiny opening nestled inside the larger one. If you cannot see the tiny opening at all or if you can see it but notice that it is clogged with dirt or dust, you may just need to clean this hole.
Use a can of compressed air to blow the dust and dirt off of the end of the innermost tube. Check it with the flashlight to see if all the dust has been cleared.
Turn the gas valve back on and attempt to light the pilot. If it still does not light or light properly, proceed to the next step.
Shut off the main gas valve and remove the entire pilot assembly by unscrewing the nut at the base of the assembly with a small adjustable wrench.
Blow compressed air through the back of the pilot assembly so that the air flow is blowing toward the pilot flame tube opening.
Reinstall the pilot assembly using the adjustable wrench. Make sure the nut is installed tightly.
Turn the gas valve back on and attempt to light the pilot light. If it still will not light properly or at all, contact a gas fireplace service specialist to clean or, if necessary, replace the pilot assembly.