Gas fireplace

Can a LP gas fireplace vent into an existing masonry chimney with no type of liner, besides the original clay/vitreous flue liners? There was a hole cut on the top of the metal insert to vent up through chimney, and that’s it.
Thanks in advance for any helpful insight.



After doing a little research… a “top-vent” fireplace, anyone familiar with these?

No and no unless the fireplace is rated as “vent-less”, then it doesn’t even “need” the chimney.

Regardless, always call for a Level II with all fireplaces, even gas. Here’s another reason why!!!

Thanks for the reply. However, I would like to know more about top-vent gas fireplaces. It seems that the vague info I can find says that these can be vented into an existing masonry chimney as long as the chimney is lined. Anyone?

I don’t know. If they say they can, then I suppose they can. Why don’t you call around and find a reputable chimney sweep and ask them?

There are standards for vents and draft. Learn them if you want to call it.

Yes you can vent into a lined chimney of everything about it is correct.

Did you do a spillage test, draft test, co test under “worst case” CAZ?

If not, I guess this is outside of your scope.

It is outside the HI SOP as you are lighting fires…

If the hole was “cut” in the top of the unit and was not a pre-stamped metal “knockout” for the specific purpose of venting, any certification that the unit had would be invalid.

:twisted:You can not have a gas fire place interring into a brick chimney ,it will undermine the liner and if no liner it will undermine the brick work.
thats point 1.
Second the gases that are toxic may find there way into the home and cause sickness or even death.
3 the gases are also acidic and will break down the liner if Terra cota or destroy brick.
Please do note that it,s a hazard.
In Canada ,Montreal ,it must be lined with a stainless steel liner or galvanized.
I am a mason and do brick restoration for a living .
PS also belong to internachi and I am a home inspector.