Greg, the roof cap is tight and we can't find any drafts. The pilot goes out when the electronics shut down. Any thoughts?

Coleman Presidential 7670 856 The pilot light blows out once the thermostat temp is reached. We've replaced the thermocouple, the gas valve, the thermostat and the filters. The unit works great, gives plenty of heat, the pilot lights easily and we've got a nice blue flame, but once it reaches tempe...