Was checking the ignitor in a fireplace today and the gas line beneath the brick flooring was leaking into the ash cleanout and ignited big time. I let it burn until I could smell raw gas and then I shut it down. Everyone was getting excited except me;-)
trouble maker…
I started a gas fireplace once and the gas valve was bad and had delayed the start. I turned it on and about 10 seconds later it shot flames 2’ out of the fireplace. Scared the crap out of me, the buyer and the seller who said she never used it in the 2 years she owned the home.
Yes, that to a BIG one 
I am waiting for the day I loose my eyebrows.
Why wait? Shave them down and let’s have a look.
That’s one reason I don’t light them.
Either way it will not be pretty… You will have to wait. 
Had a student job shadowing me last week and an ancient furnace had a really long delay on the ignition after the gas valve opened. He was across the room so I didn’t bother warning him even though I was backing up. :mrgreen: He let a few colorful words fly when it finally caught and shot a flame out of the front accompanied by a resounding boom. 
Too much fun.
No need to check gas lines here (I still do to some extent but I don’t turn on ignitors). It’s mandated here that the seller will provide a complete report by a qualified gas contractor before close of escrow.
If the pilot or ignitor is not on, they I don’t turn them on. They may be off for a reason. Recommend having it further evaluated by a licensed technician.
Always remain attentive while working on a fireplace and always get the observations that from where we are getting the right deals. Because of the some unfortunate reasons the things must be gone work badly on to it.