Fireplace question

[Acorn]

My MIL had a wood burning fireplace, she had gas logs installed in.
When I close the damper it doesn’t fully close. It has a couple inch gap.
It should close completely, correct?

 

[AJGUNNER]

It should close completely, but if the gas logs have a pilot light burning, it might be wise to leave the damper partially open.

 

[Jimbo357mag]

On many gas fire places that have ceramic logs with sand and embers that cover the burner and are made to burn with a natural yellow flame the damper has to be somewhat open to allow venting. The manufacturer will include a metal bracket that attaches to the damper to stop it from closing all the way. Anytime there is a yellow flame there must be an open damper to get the CO out.

There are some gas heaters that have an open burner and a blue flame for heat that don't require an open damper in fact many of those are installed in front of the fireplace.

There are also enclosed fireplaces that have an air intake and exhaust that must be run to the outside via vent piping.

 

[blume357]

the damper should be open fully or at least half way when using the gas logs... most likely the installers put a c-clamp on the damper plate or handle so that it can't close completely. Vented gas logs put out soot and the manufacturer of the logs require this in the installation and they claim it is for the users protection but in reality it is for their protection for when the user forgets to open the damper. It really has nothing to do with the pilot light... it is possible depending on the age of the house and the idiot brick layers (sorry I'm being redundant) who built the chimney that they left mortar around the damper frame and this is causing it not to close completely. If you want more information then just private message me or ask here. I've been crawling in and on chimneys for over 39 years for a living. I deal with gas logs pretty much every day.

All of this is dependent on the type of gas logs, type of chimney and a lot of other things.
(ventless gas logs are evil and the worst invention of the 20th century)
vented logs are designed to burn the gas incompletely and have dancing yellow flames to look more real and this is why they put out soot as well as a good bit of carbon monoxide. The rule of locking the damper open on these, like I said is for the manufacturers protection, and is just plain stupid.... massive heat loss in cold weather and the only solution is glass doors which the folks that sell logs also sell.

 

[trebor44]

Venting is a life saver and needed for fireplaces and stoves (wood, coal etc.) You really don't want to 'lock in' the fumes.

 

[Acorn]

Just to clarify, I understand the issue of CO.
I want to close the damper with the pilot light out.
Natural gas prices here are going up, so we haven’t run the fireplace.
With the damper open and even with the glass doors closed it gets cold in the basement game room.

 

[LGC42]

Code requires that dampers must be locked open when gas logs are installed.

 

[Jimbo357mag]

Just to clarify, I understand the issue of CO.
I want to close the damper with the pilot light out.
Natural gas prices here are going up, so we haven’t run the fireplace.
With the damper open and even with the glass doors closed it gets cold in the basement game room.

If you do not wish to use the fireplace logs I would suggest putting a piece of plywood in front of the fireplace to block the air from going up the chimney rather than trying to close the damper all the way.

 

[blume357]

Look up in there... as I said there may be a C clamp on the damper or handle... if not then just look over the frame and there might be some mortar on the sides or front that is causing the damper not to close all the way. I often do the non industry speak and just write on my forms for the customer: "Damper Must be open when using logs" I mean how hard is it to understand this... half the year the pilot light exhaust is not going up the chimney anyway. If you can't get it to close all the way then turning the pilot off and putting something over the front is a good idea. Just don't do what I've seen some folks do... seal the damper shut with Great Stuff.... they (idiots) are out there.... I've even seen them try and patch hols in a fireplace with this stuff... the really 'smart' ones use the firestop Great Stuff... which is still combustible by the way....