Reuben's Home Inspection Blog


My Beef With Old Gas Log Fireplaces

Reuben's BeefI'm not a fan of gas log fireplaces because they waste energy and they're a potential safety hazard.  These fireplaces start out as wood burning fireplaces, but at some point someone decides that building a wood fire is too much work and artificial firelogs are ugly, so they have a gas log installed.

Most gas logs are pretty simple; they basically consist of a pipe with a bunch of holes.  Gas comes out of the holes, the gas burns, and the exhaust gases go up the chimney, just like when you build a fire.  Sounds good so far, but hold on.

Gas Log Fireplace

What happens if the damper is closed?  If the fireplace damper is closed when a gas log fireplace is operated, the combustion gases will come right in to the house.  While you have the same potential for this to happen with a wood burning fireplace, it will be quite obvious if a wood burning fire exhausts in to the house; everything is going to get very smoky, very quickly.

When the combustion gases from a gas  log fireplace come back in to the house, it's not nearly as obvious; in fact, it could be very easy to miss.  These gases can contain high levels of carbon monoxide, making this a safety hazard.

Damper clips are supposed to fix this issue.  To make sure the damper never gets completely closed on a gas log fireplace, there is supposed to be a damper clip installed.  This damper clip will prevent the damper from closing all the way, and is supposed to prevent the exhaust gases from coming back in to the house.  San Diego Home Inspector Steve Stenros actually blogged about this clip being one of the most common write-ups at his home inspections.

Damper Clip

I've tested several damper clips to see just how effective they are, and many of them don't do their job.  These damper clips will often allow to damper to close most of the way.  When the damper is mostly closed, most of the exhaust gases will still come back in to the home.  To work properly, a damper clip needs to keep the damper open all the way, or at least most of the way.

When the damper is always open, which is how these fireplaces are supposed to be installed, there will always be warm air leaving the house through the chimney, cold air coming in to the house through the chimney, or both. This is a major source of energy loss.

New Gas FireplaceMy recommendation:  Invest in a newer direct vent gas insert.  These have a two-pipe system, which allows them to bring in air directly from the exterior for combustion, instead of using the air in the home.  While they're usually not intended as a heat source, they kick out a lot of heat, especially if there is a blower fan installed.  My wife loves our gas fireplace, and I don't have any specific problems with it.


Reuben Saltzman, Structure Tech Home Inspections


Comment balloon 36 commentsReuben Saltzman • September 06 2011 05:52AM


Reuben.....I had a gas log installed in my last home in a center chimney.....I had the damper removed and bought a set of very efficient, insulated around the edges, glass doors....I know it wasn't the most efficient but I didn't want any accidents.

Posted by Barbara Todaro, "Franklin MA Homes" (RE/MAX Executive Realty ) over 7 years ago

Barbara - hey, you did about the best thing you could do without replacing the fireplace.  

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

The fireplace you picture has a problem already with combustion as demonstrated by the charring on the logs!  That's a CO indicator right there!

And how often now are builders putting in "ventless" fireplaces!?  I see them all the time.  And they always have "that odor."

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Ventless fireplaces?  Bad times!  I've heard of 'em, and I occasionally find one in a garage, but I've never seen one inside a house.  We have a building code amendment here in Minnesota that prohibits those things :)

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

I was wondering about ventless fireplaces too because I see them advertised, but the direct vent type makes more sense.  Thanks for the information.

Posted by Peggy Chirico, REALTOR® 860-748-8900, Hartford & Tolland County Real Estate (Prudential CT Realty) over 7 years ago

I've had both gas and wood fireplaces over the years. One has to make sure the damper is open with either. Didn't know gas fireplace dampers were supposed to be blocked partially open. That would be ok in a warm climate such as Vista CA, but would be terrible here in Newton MA. 



Posted by Melissa Ostrom & Melville Capps Newton MA - The Mel and Mel Team ((617) 388-3151 | Century 21 Commonwealth) over 7 years ago

Reuben, we converted to a gas fireplace insert a few years ago. It was a good move.

Posted by Michael Setunsky, Your Commercial Real Estate Link to Northern VA over 7 years ago

Reuben, thanks for the posting, I learned something about gas fireplaces by reading it.

Posted by Michael L. Brownstead, ABR, GRI, MRP, SRS, 1SG US Army (Ret.) (Keller Williams Realty) over 7 years ago

The damper clip was an issue with one of our house and I am surprised how difficult it was to find it. 

Posted by Mike Yeo (3:16 team REALTY) over 7 years ago

Have to say I love me gas logs, we so infrequently use it and during non use it looks much nicer. When we do use it, my husband always throws the damper open. 

Posted by Corinne Guest, Barrington Lifestyles (Barrington Realty Company) over 7 years ago

there's always the option of ventless gas logs (which are safe and very efficient).  As for my personal taste... I have a wood burning stove and I love it.

Posted by Tammy Lankford,, Broker GA Lake Sinclair/Eatonton/Milledgeville (Lane Realty Eatonton, GA Lake Sinclair, Milledgeville, 706-485-9668) over 7 years ago

Interesting post.  I'll have my husband check the damper today.  If it's open we would loose cool air all summer.

Posted by Team Honeycutt (Allen Tate) over 7 years ago


This is a good point. I'll watch for that in resale housing.


Posted by Brian Madigan, LL.B., Broker (RE/MAX West Realty Inc., Brokerage (Toronto)) over 7 years ago

Gas fireplaces...ugh. Ugly, wasteful, and dangerous. Ventless...they do stink and "something" is causing that odor...hmmm...wonder what it could be?

Posted by Mike McCann - Nebraska Farm Land Broker, Farm Land For Sale 308-627-3700 or 800-241-3940 (Mike McCann - Broker, Mach1 Realty Farmland Broker-Auctioneer Serving Rural Nebraska) over 7 years ago

Never a fan of them. The aesthetics suck, and your explanation is another reason why I love my fireplace. 

Posted by J. Philip Faranda, Broker-Owner (J. Philip Faranda (J. Philip R.E. LLC) Westchester County NY) over 7 years ago

I love my direct vent gas fireplace.  It is not a great heat source, but the clean up is EASY.

I see issues with fireplaces all the time- damper issues, chimney caps, ect.  Most home owners do not get how dangerous these can be.  Great post- most do not know what a damper clip is. 

Posted by Timothy Mattingly, Louisville Homes for Sale (Louisville Homes Team Louisville KY over 7 years ago

Hi Reuben! I like the T-bone steak in the upper corner! I once walked into an inspection only to see a soot-covered living room. The seller had used her fireplace for years and had no idea there was a damper in there! Sure enough- It was closed tightly! And I agree, most of the time the damper clamps are incorrectly installed!

Posted by Steve Stenros, CREIA MCI, ICC, ACI Home Inspector,San Diego (Poway,La Jolla,Del Mar,Mira Mesa,Carlsbad,Escondido,Temecula) over 7 years ago

I have the same set-up as my colleague Barbara does in apt #1 upstairs...Also, there is a guy locally here that dresses up the gas unit with rocks, embers and artificial logs that is like looking at a Xmas setting. Expensive but worth it. I will be the first to admit that I went to gas because there was no clean up and it lit instantly and stayed lit. I do miss the smell of the different woods, the crackling and the feel..good post.

Posted by Richie Alan Naggar, agent & author (people first...then business Ran Right Realty ) over 7 years ago

Thanks for the excellent advice, Reuben.  This information many of us can use personally and professionally!! I have gas logs in my fireplace. 

Posted by Mike Cooper, GRI, Your Neighborhood Real Estate Sales Pro (Cornerstone Business Group Inc) over 7 years ago

Replacing these type of fireplaces have become much more economical Reuben, and the energy payoff might help to compensate for the cost.

Posted by Chris Smith, South Simcoe, Caledon, King, Orangeville Real Esta (Re/Max Chay Realty Inc., Brokerage) over 7 years ago

Reuben, good post---see this all the time.  Even chimneys with a closed damper typically do not seal tight enough to prevent the waste of energy up the flue.  Gas fireplace inserts (sealed type units) are for sure the way to go.  Most people don't realize these gas inserts are more efficient than their furnaces.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

Very interesting.  Did not realize how unsafe gas fireplace could be.  I was never a fan of artificial logs even though they are convenient.  For me, real wood or nothing.

Posted by Ira Bodenstein, NMLS#: 445143 (PNC Mortgage) over 7 years ago

We finished off over 1,000 sq. feet in our basement and our vented gas fireplace(in that area) throws out MORE than enough heat !!!!!

Posted by Michael J. Perry, Lancaster, PA Relo Specialist (KW Elite ) over 7 years ago

Peggy - stay away from ventless gas fireplaces.  They produce a ridiculous amount of moisture.  "Room vented, lung filtered."

Melville - good point about the differences in climates.  I'm sure that a damper clipped open isn't nearly as big of a deal during a balmy CA winter.

Michael S - I don't know of anyone who regrets making the change.

Michael L - thanks for reading.

Mike Y - if you were looking for a part that was designed specifically for a fireplace damper, I can understand how this would be tough to find.   Many damper clips are really just re-purposed pieces of hardware, readily available at any hardware store.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Corinne - gas logs certainly are the closest thing to a wood fire without actually have a wood fire.

Tammy - I'm not a fan of those ventless fireplaces; they're actually not even legal here in MN, because they produce a lot of moisture, which is bad for the house.  

Team Honeycutt - glad to help.

Brian - I'm sure you'll find it :)

Mike M - you've ruled out most fireplaces.  What's your preference, wood burning?  Wood fires cool the entire house down...


Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

J. Philip - wood burning fireplace, I assume?

Timothy - switch on, switch off :)

Steve - wow, you must have smelled the soot from outside the house!

Richie - I know exactly what you're talking about with the 'dressed up' look.  Those really can look pretty authentic.

Mike C - thanks!


Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Chris - eventually, I'm guessing it would.  It's funny how much more heat the newer sealed fireplaces produce.  I couldn't get my face more than about two feet away from one at a home I inspected this morning.

Charles - you're right about the dampers.  Growing up, my dad always had the basement fireplace completely sealed off because so much cold air would dump down in to the basement, even with the damper closed all the way.  On the upper levels, there is just as much air moving, but people just don't notice because it's air leaving.

Ira - I had the same attitude about gas fireplaces as you... until I moved in to a house with a gas fireplace.  Now it's nice to flip a switch :)

Michael - even though they're technically called 'decorative gas appliances', they create a ton of heat.  Add a blower fan, and they're enough to heat a small, well-insulated house.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

I love fireplaces and the one we have is wood burning and we check the vent all the time.  I have heard pros and cons on gas fireplaces but I think on the flip side, if one has to leave the house immediately, they don't have to worry about the wood logs burning. 

Posted by Barb Van Stensel over 7 years ago

Hi Reuben, Thanks for clearing this up. I've always wondered about it and I never read info on it before. Nice job!

Posted by Sandy Acevedo, RE/MAX Masters, Inland Empire Homes for Sale (951-290-8588) over 7 years ago

I've got one of those old fireplaces. I don't use it and wish I had never let the builder install it. There is not even a blower on the builder grade one he installed and the heat goes right out the chimney. Live and learn.

Posted by Gregory Bain, For Homes on the Jersey Shore (Mezzina Real Estate & Insurance) over 7 years ago


Great article. Luckily I see mainly direct vent units so this is not a major issue here.

Posted by Donald Hester, NCW Home Inspections, LLC (NCW Home Inspections, LLC) over 7 years ago

I have never liked the fact that you have to leave the damper open. Hey, but it keeps the birds and squirrels warm all winter.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) over 7 years ago

Barb - that's a good point.  One more reason to go gas.

Sandy - thanks!

Gregory - ha!  Boy do I know about builder grade 'stuff'.

Donald - you must look at a lot of newer houses.  Lucky.

James - and it's always a shock when you stick your face over the chimney and find one :)

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Reuben, that little guy has a nice built-in chimney brush---maybe he was just "working":)

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

At least half the time my inspections find open dampers that should be closed. That means that many homewoners are not very aware of the condition (open or closed) of this fireplace equipment. For that reason I share Reubens concern about the safety of these converted fireplaces.

Posted by Robert Butler, Montreal Home Inspector | Aspect Inspection (Aspect Inspection) over 7 years ago

Charles - not very hard, given the white coat of fur ;)

Robert - I find the same thing.  Lots of dampers wide open... 

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago