Gas log conversion question

The wood burning fireplace has a Gas log conversion. The damper has a device installed to hold the damper open as it should. Now for my question…Does the damper need to be held open FULLY? The way this device is on there, the damper can be closed most of the way, leaving it open approx. 1/2". I couldn’t find anything other than the flue must have something to keep it from closing. Thanks in advance…Rick

Sorry no pics.

That a tough one with out seeing it.

It’s just a typical damper with a clamp type device that keeps it from closing all the way. I was just curious whether it needs to be held alll the way open , or is the half inch opening considered enough. It can be manually opened all the way.

On all of the gas logs that I’ve installed, the damper only needed to be open slightly.
I had one customer that insisted I leave the clamp off.
He said “I’ll open it when I light the logs”.
I told him, I’m sorry but I am required to put the clamp on.

There is a big difference in flue size required between those small BTU gas logs and burning wood.

Thanks Sparks!

just a little

Gas logs burn dirty and produce toxic gases.

Regardless of combustibles, flue gases still require a calculated amount of vent area.

You need a flue capable of venting the amount of BTU combusted gases and you can’t cram 10 lbs of sh!t in a 2 lb sack.

I’d check the instructions and BTU rating.

A 1/2" opening along the width of the flue would probably not be enough free vent area to properly address most units in the market place.

Just on the safe side I advise clients to fully open flues when using their fireplace regardless of the fuel being burned.

Any other advice is just flirting with disaster, imo.


They remove the dampers on conversions in my State.

That is without a doubt the best advice to be safe unless the manufactures installations are available.
Better off to unnecessarily lose a bunch of heat up the chimney and be safe IF any doubt at all.

I said all the gas logs that I’ve installed but there are probably many more that I haven’t seen, I’m sure.

But I still say a fireplace designed to burn wood will always have a much much larger flue than is needed for these small BTU/HR gas logs.