If you have a water heater tank that uses natural gas, you may be able to cause the exhaust (carbon monoxide) to flow into your house. A good thing? Not at all, but at least you’ll know if backdrafting may be a problem or not. And knowing is half the battle (thanks, GI Joe).

1. Turn on every fan that sucks air out of your house (dryer, furnace, bath fan, kitchen fan, etc).
2. Wet your lips.
3. Starting with the room farthest from your water heater, with your back towards the water heater, close each door to a sliver, and feel on your wet lips if air is blowing at you. If it blows, leave it closed!
4. The most common set up in a home with a furnace is every door in the house closed, except the doors between the furnace return and the water heater.
5. Once you arrive at the water heater, turn up the temp until it fires, and place your hand near the draft hood (the opening just above the flat top of the tank).
6. If you feel warm wet air escaping, your water heater is backdrafting. Turn off the fans, air out the house, and call a professional.
7. No warm wet air? You either are not backdrafting, or you set up the home wrong.