Either vented or non vetoed gas longs. How open does the flue have to be open. I lose a lot of heat the way it is set now Flue is set to wide open. Can I ajust the stop on handle to close it to @ 2 to 3 inches in the open position
You should be able to dampen the flue as you would with a wood fire to slow burn rate. Bring it down slowly and monitor for smoke intrusion. It doesn't take much to maintain a chimney draft--maybe 25% open.
Do keep a carbon monoxide detector in service as a safety precaution.
Hmmm thinking, you have a gas burning appliance with a designed flue size to vent the proper exhaust gasses out so nobody gets killed from carbon monoxide poisoning and you are wondering if you can close it down in order to get more heat out of a device meant for looks instead of heating. I think the answer should be exremely simple, if you want to continue living just leave it alone. If you feel the need not to wake up one morning or the same for your wife and children if you have these then by all means play with things you should just leave alone. Those were designed for romantic evenings, with the love of your life summer and winter. Just because it's winter and you want heat from it too, then go out and buy the apporpiate appliance to heat your room don't play with things not designed to be played with