I have it set on standing pilot, which stays lit. The unit is only 2 years old and was working fine a few weeks ago. Temperature outside is above 50 degrees, and our main gas hot air heat is working fine. No soot build up around thermocouple which was my first guess. The remote control does not seem to be sending out any signal when this is happening either. The fire seems to go out at random times, sometimes after 15 seconds or less, or after several minutes, but will come back on after less than a minute later usually. Any other ideas?
If remote is in 'smart' mode, it will cycle the flame to maintain the selected temperature. If remote is too near the fireplace, it will heat up quickly, turn off, cool and turn back on for a little while until it heats back up. Try moving the remote further from the unit while it's lit.