Q: Jason, My water heater vents into the chimney for the fireplace in my basement. Is it OK for me to put a Chimney Balloon in this fireplace? – LT
A: LT, By the looks of the location of where this vent from the water heater enters the chimney you should be able to put a Chimney Balloon into the fireplace as long as you put it BELOW the location where the heater vent meets the fireplace chimney. When you look into the fireplace and look up into the flue can you identify the location of this connection? If yes then measure an area below that point for the Chimney Balloon. Just to be on the cautious side I would put a Carbon Monoxide detector in your basement near the fireplace and the water heater to make sure the chimney is still drafting properly and the Carbon Monoxide is not backing up into the basement when the water heater is running. It is a good idea to have one of these devices on every floor of your house anyway.