Question: Hi. I'm installing a gas fireplace or stove and want to know if I can vent the fireplace through my existing gas furnace vent pipe.I got a new furnace and they vented it out the back of my game room and they capped the pipe going out the chimney.The water heater is vented through the same chimney. So what I am asking is can I vent my new gas stove or fireplace out the existing pipe that was capped off. The pipe is 5 inches in diameter.If not what are my options? I want to install the fireplace or stove in the middle of my game room eliminating the direct vent options.THANKS!! Answer: Jody, If you use a natural vent, or "b-vented" type product, you may be able to use the existing flue as most of these products use a 4" vent. That's what makes them versatile. But, the bottom line, however, is whether or not that type of installation will be acceptable to the manufacturer. Height, elbows, location, etc. all play a factors in this. My recommendation: narrow down your picks on products, and have a gas hearth products installer review the installation vs. the brand's requirements. Otherwise, it's a shot in the dark. I could say "yeah, it's okay," you then find the unit you want, yet the manufacturer say's it's not listed for that application. Back to ground zero. Take lots of pictures, write down dimensions, and bring it to your retailer. That's the way to start this project safely.