A Wood Stove Needs a Separate Chimney Flue

LESLIE: We’ve got Luke in Maine who’s got a question about installing a wood stove. What can we do for you, Luke?

LUKE: I only have one chimney in my house and I’d like to add a wood stove to the same flue that my furnace is on. How safe would that be?

TOM: Very not safe. (laughing)

LESLIE: Ooh, because they both operate on different chimney systems.

TOM: Yeah. If this chimney has one flue, as opposed to a chimney that has two flues, you could have one chimney with the wood stove on one side and, I presume, gas or oil on the other. But you cannot mix the combustion. So you can’t have a fireplace or a wood stove using the same flue as your gas-fired, oil-fired or propane-fired furnace. That would be very dangerous.

So the other thing to think about is whether or not you might want to put in, say, a direct vent fireplace; one that is zero clearance; one that can go against a combustible wall or surface and vent right to the outside. Or you can run the vent pipe up the exterior of your house. Or you could always build a new chimney but, of course, that’s the most expensive way. But no, you cannot share the same flue with both gas combustion and wood combustion at the same time.

LUKE: Now … okay. So I can have my hot water tank with the same …