Although these units have very few moving parts, they do need periodic preventive maintenance, probably best done by a professional. Ours, a different brand, is still too new to need any maintenance -- preventive or otherwise. How often you do it depends in part on how much you use it, assuming that certain components get dirty and need cleaning out. I think once a year is probably too often unless you use it as a main source of heat.

But I haven't anwered your question. I think it needs diagnosis by a professional who knows exactly what to do to troubleshoot. Here's my speculation: If the thing sometimes stops firing spontaneously, and then goes back on spontaneously, that suggests that the vent that provides oxygen to feed the combustion may be partly clogged. That should not happen if the right kind of cap was installed on the chimney, but it's still possible after a period of time. If you can easily get to the chimney top without risking life and limb, go up there and see if anything obvious is clogging it.

Thanks for your response. Fireplace has been serviced each year and approx. 4 months prior to this problem. Should have said that when the unit quits it will only respond when the wall switch is turned off then on. However, propose to have the service rep. take a look. Better safe than sorry...

Odds are that the pilot burner is dirty or the wall switch is defective and needs to be replaced. Presumably the pilot has been cleaned when the fireplace has been serviced, so I'd try taking the wall switch out of the wall and shorting the wires together, which mimics closing the switch.

If that causes the fireplace toi turn on reliably, install a new switch.

Does the Skytech 3301P2 remote control work with the Napoleon GDS60 gas stove?

I vote for dirty thermocouple.