These problems creep up in fireplaces with inadequate chimneys; usually pre-fabs. If the stack isn't a few feet taller than the TALLEST part of the roof on the entire home, the stack effect of the house competes with the chimney reducing it's draft - especially after the hot fire dies down. If you're that worried about smoke outside (understandably you don't want smoke in the house) then just don't burn anything. Modern homes with inexpensive poorly designed chimneys (unfortunately the norm) will have these problems with any fuel, there's little you can do other than change the system.

As far as the duraflame's themselves, yes, they tend to do what you describe. A small, cool fire doesn't produce enough heat in the firebox to keep itself going after it has burned down to a certain point and the smouldering pile of wax and wood chips is what you end the night with, although not a problem inside if your chimney is drafting properly.

Hi Berlin,

Thanks for the response, but my house is not modern. It's actually a 1940 house and my chimney is 4ft+ tall. I am attaching a picture.

Thanks

In your case, the problem is not height over your roof, but rather, height in relation to surrounding objects, lack of thermal mass, and, most importantly, lack of overall stack height. Looks like it was some kind of early "pre-fab" steel firebox, probably not original to the house, but possible.

It's definitely original. So bringing the chimney higher would help with draft? Might not even be allowed by code.

Thanks

bringing the stack a few feet higher would help with the draft, you should have at least 15' from the fireplace throat to the termination of the stack, more is better. As far as code, it would be rare that you wouldn't be allowed to bring the stack higher - where you run into problems is finding a double or triple wall stack that is listed to meet with your existing stack and inspectors don't like to see anyone switching brands or styles of pipe on the same stack.

The fire alarm in our house went off because of our Duralflame/wood log combo fire in our fireplace that created a smoky mess! The firemen said not to combine wood logs and Duraflame logs?! We never heard that before, but, needless to say, the beautiful dinner party we were hosting turned into a crazy Seinfeld episode when the fire trucks had to return twice :/

Having the chimney cleaned today and sticking with real wood from now on!

P.S. We also had the distinct honor of meeting our local firefighters who not only saved us from noxious fumes with giant fans, but were kind, professional and humorous!!