If the gas is leaking it stinks to high heaven but when it's burning it's ok. I find though it makes the air dry and my eyes itch with it. We have central heating that's also gas, just turn it on and the house is warm. Boiler for that's in the kitchen though. Having them both serviced this work so they are working ok for the winter.
have you tried maybe putting a cast iron tea kettle or pot in front of or on top of the "fire" that would add a little humidity and not use any extra power. maybe with a little vanilla or cloves in the water then you have good stinkums