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Flue/Damper - probably a pretty basic question..!

Hi & thanks in advance for the help.  I have a gas fireplace (recently converted from woodburning) and the damper doesn’t close all the way... see the photos.  Should I just remove the screw so that it sits properly/flush when the flue is closed?  Currently there’s a gap as pictured even when in the ‘closed’ position so there’s certainly hot air escaping up the chimney.  Just wasn’t sure what the screw was intended for / doing.  Thanks for any advice and intel!!


  • Jamie Hall
    Jamie Hall Member Posts: 23,272
    How does the gas burning fireplace itself exhaust? If it's not a direct vent of some kind, you really do need that chimney to draw at least a little, so the combustion products go away and not into your house, where you really truly don't want them.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EBEBRATT-Ed Member Posts: 15,512
    If the fire place has a gas pilot (which it does) the flue must be left cracked open for the pilot.
    JUGHNE Member Posts: 11,058
    You could ask the installer.
    That was recently added, it is a beam clamp and too clean to have been there in the wood burning mode.
    It was most likely added for the pilot and to assure that you had some draft when lighting the gas.
    Do you open the damper more when burning gas?
    Alan Welch
  • Bob Harper
    Bob Harper Member Posts: 1,034
    Any vented logset is required to have the damper completely removed or fixed to maintain a minimum PERMANENT net free opening specified by the mfr. This is in the gas code, the ANSI Z21.60 or Z21.84 listings for vented logs. Most mfrs. start at 50 sq. inches which equates to an 8" round flue. The net free area of a damper cracked open as shown does NOT meet that std.. I teach to put the supplied damper clamp on the damper handle at the buckle propping it wide open 24/7/365. In Taxachoosetts you take the damper out or weld it wide open.
    If you have a remote control, it needs to be fixed wide open anyways. Nobody is going to get up, use Feel-A-Vision getting soot all over their hand wrestling with the damper handle to open it, often knocking it off track each time before you wash the soot off your hand, sit down and then zap the remote.
    The best you can do is install a snug fitting set of high quality glass doors.
    Your other option is to replace the logset with a direct vent insert. These have liners for intake air and exhaust to a combustion chamber sealed with glass. If the top is packed with rockwool, you don't get cold air infiltration, bugs, odors, or sounds megaphoning down. You don't suck 400-600 CFM of conditioned air up the chimney every minute but instead supplement that zone with about 30MBH while enjoying a realistic logset, flame and embers. Most remotes come std. with a multi-function remote to control flame on/off, thermostatic mode, fan speed and sometimes an accessory light to enhance the effect or to provide some glow in warm weather when heat is not desired. These units are listed as vented room heaters and thus legally allowed to be thermostatically controlled. They also come with a battery backup for use during power outages. It's the safest option that does not require major repairs.
    A vented logset should only be installed into a working fireplace suitable for continued wood burning. If it flunks a level II inspection, which 99% will, it must be relined or restored prior to installing vented logs.
  • jasonh595
    jasonh595 Member Posts: 2
    Got it — thanks all!