I am sure you have checked, but are you 100% certain that the damper is
fully open? It may not have enough draft.


Have you tried opening a door or window about 12 inches (in the same room)
to see how it draws ? It is possible that your house is TOO airtight,
and your fireplace doesn't have enough air to feed it efficiently.


Of course, you would also want to go up on your roof with a strong light of
some sort, and make sure there is no physical blockage of your flu. (You
may be able to do this from the inside, depending on your damper
arrangement, and whether you can remove it to inspect up your flue).


You are correct about one thing. It often takes a while to get the flue to
warm up before a fireplace will draw well. This may take a while, depending
in part on the type of wood you are burning.

I hope these ideas help, please let us know !!


--James---