Connecting a wood stove to my furnaces chimney

Discussion in 'Alternative Energy' started by NJ Rich, Sep 12, 2006.

  1. NJ Rich

    NJ Rich NJ Rich

    Dec 14, 2005
    Springsteen Area of New Jersey
    There is a upright round wood stove I can get for free. It isn't one of those "air tight effiecent models". I really don't care about that. I am thinking of getting it to supply heat if the natural gas fuel supply is interrupted.

    I would want to disconnect the gas furnace exhaust and connect the wood stove to the cement block chimney. I can do the pipe work and have it ready if the need comes about. The flue pipe connection we have is 6 inches. The distance from the top of the wood stove to the chimney connection is about 20". I think the stove pipe is different than that used for natural gas. If I am correct and need a different pipe please put me on track to get the right material.

    Has anyone done this? Are there any problems I should be aware of? Of course I would shut off the gas and power to the furnace before making this change over. Help.... NJ Rich
  2. rambler

    rambler Well-Known Member Supporter

    Jan 20, 2004
    Currently it is not to code to share a chimney between oil & wood stoves. Tho there is not a big chance of problem.

    It has been totally illegal to place gas & wood appliances on the same chimney. Real potential for a problem there.

    I'd think long & hard on this one before trying it....


  3. TheBlueOne

    TheBlueOne Well-Known Member

    Jul 2, 2004
    The pipe you're looking for is black and is a heavier material than dryer vent. It's available at Home Cheapo although early in the season they may be sold out of some of the componets. Make sure to put a cast iron damper on the flue to help control the burn and depending on the dynamics of the chimney, you may need a barometric damper if it drafts too strong. Absolutely do not use anything else other than "stove" pipe. You can potentially see flue temperatures of 800-1000 degrees F; that's what stove pipe is designed for.
    As far as violating any codes, if you're unhooking the gas furnace and hooking up the wood furnace, both are not coneected at the same time. If the chimney is going to be used for wood it should have a cleanout port at the base to remove ash & soot.
  4. Ross

    Ross Moderator Staff Member Supporter

    May 9, 2002
    Wood oil combo's can be to code, certainly here In Ontario it is. Wood +gas, I couldn't say, but you'd want to use that lined block chimney and not the Gas B vent (or oil's L vent as it's not insulated) ! Check the clay liner (assuming it has a clay liner) isn't flaking off from condensation and freezing from the gas exhaust. Not a lot of heat goes up a gas vent! You may need to reline the chimney. Stove pipe for a wood burner is black as the stack temp will go above 700 degrees F and that will cause the galvanizing to flake off regular C vent pipe. You connect wood stove vent backwards from oil so it's the crimped narrow end into the stove and the next into that pipe leaving the wide end to towards the chimney. Not as smoke tight BUT if you have a chimney fire from cresote the burning molten tar runs down the pipe into the stove and not out of the pipes in an open air flaming mass!