I've never seen that on a gas appliance, only one or the other.

Is there an electric switch and a gas valve to increase flame?

Which, frankly, I wondered about, this summer, but it wasn't using hardly any $$ so I never got around to questioning whether it SHOULD remain lit (and frankly, I detest the thought of re-lighting a gas pilot myself)

Modern gas burners have a safety feature of a optical light detector that shuts off the main gas flow if a flame is not "seen". it will allow the gas to come on when the burner is activated, but if it does not "see" a burner flame, it will shut down the gs flow to the burner. Basically to keep your house from filling with gas if the burner doesn't light or goes out for unknown reason.

That said, I'm no expert and I would have service person look at it.

Now, I just have to figure out who to call (this is my first gas fireplace and frankly gas scares the bejeebus out of me). Hell, I always made the gas company come out if the pilot went out on my hot water heater.

that dissuades me from relighting a lot of pilot lights, so I'm with you there. I have arthritis and things get painful fast.

However, what you have is most likely either a wiring fault or dirty sensors. Percussive maintenance might work for a little while, but it won't work for long and given the nature of glass, should definitely be discouraged.

You're going to need a professional to come out and check the system. It's likely an easy fix once it's diagnosed.

They'll have either their own maintenance guys/installers, or be able to give you options.

However, I recommend picking one that looks big and successful. I've heard a few deadly stories involving "fly-by-night" operations.

Allows enough opening to keep the pilot lit, but not enough for the burner. Bumping it and making it work makes me think about it. Also possible the mount of the thermocouple is a little loose, and it's slightly out of position, but moves when bumped.

Just an idea - I'm no appliance repair person, but we own rental units, and I've replaced many parts of gas furnaces and fireplaces. A $10 thermocouple has made more than its share of trouble through the years.

Just a thought.

Injunction against tapping on glass is mainly about not doing it to hot glass. Cold glass is no more an issue than the glass in your windows.

If you feel competent, you might take the cover off and look for anything obviously wrong, ie a spiderweb in/over a sensor, or an excessive accumulation of dust. But anything that's the heater itself, even if you're pretty damned sure it's that loose connection right there, leave to the experts.