Chimney Balloon fireplace damper

Wood fireplace with gas starter is very cold, how can we insulate it?

Q: Jason, We have been renovating an older home from the 70's for quite some time and have just recently moved in. The problem is the drafty original brick fireplace. No unpleasant odors, just drafty cold air. We've done quite a bit to update the look, but now the beautifully tiled hearth is always cold as well as the entire room. (Even though we live in the South, our winters can get cold.)

We have resorted to putting a huge piece of cardboard in front of the firebox because we do not have any glass doors. It does seem to help but is not an acceptable permanent fix.

The damper does open and close but does not provide a good seal. There is an ash fire grate in the center of the firebox floor, from which I feel a small draft. The fireplace also had a gas "starter" which uses a key to turn the gas off and on (No pilot light). There is a good amount of draft coming from the opening around the key. This area does not seem, to be connected to the chimney or flu area so I don't know if the chimney balloon would even help with this.

There appears to be some cracks in the fire bricks in the back of the fire box, which may also be contributing to the problem. Will the Chimney ballon help? Do you think ther are other things I could do to improve situation - glass doors, repair bricks... - DE

A: Dear DE, Since you just have a gas starter there you will be fine to use a Chimney Balloon as long as you make sure the gas is turned off completely wiht the key. Turning off the gas essentially is disabling the gas starter. Be certain though that the gas is completely shut off to the starter and you mark the key or gas tap with a note that the flue is plugged.

You have a few options of where to put the Chimney Balloon. If you have at least 8” of vertical lintel area below the damper handle you could put a balloon in below the damper. If the damper is too low for that or the handle is in the way, you could also put a Chimney Balloon in just above the damper. Essentially you would open up the damper and use a folding carpenters ruler folded into an L shape to get a measurement up there. You would measure wall to wall from left to right and from front to back and that would tell you what size Chimney Balloon to get. The Chimney Balloon would rest right on top of the open damper.

Next take a close look at the ash cleanout. You can remove the cover and measure the rough opening and install a Chimney Balloon into that ash chute. I am certain the majority of your draft is coming from air being exchanged between the ash chute and the chimney. This is a very common issue since and ash cleanout essentially is and air path that connects the basement or crawlspace to the chimney and results in a strong air pull through the fireplace that makes it cold.

After this, if your still have a draft coming from the keyhole, you can look into filling that with fireplace caulk if needed. - Jason

My damper is 4 feet up the chimney and has a pull chain to open it and vents in the flue wall underneath.

Q: Jason, I have two issues. The website indicates that the chimney pillow should go above the damper. Our damper is about 4 feet up the chimney chute. It's attached to a chain and when open, the damper bisects the flue in an up and down position. Would we still position a pillow above the damper? How?

Also, We have a set of vents below the damper on all four sides. There are about 6 horizontal vents per side and they extend from right below the damper to about 8 inches below. Can I install over those? - SS

A: Dear SS, It sounds like you have a Heatelator brand fireplace. I have done many installs like this one you described. As a matter of fact there was a condo association in IL that had hundreds of these Heatelator fireplaces with butterfly dampers and vents underneath just as you described. See attached picture.

You will find a small ledge just above the firebrick lining the firebox. That ledge is a perfect spot to install a 36x15 Chimney Balloon. That area is trapezoid in shape but the 36x15 will have enough material to plug it anyway. See attached picture of balloon installed. - Jason

My fireplace is cold and it doesn't have a damper at all, should I convert it to a gas fireplace?

Q: Jason, My wife and I recently bought a fixer upper and are almost ready to move in. We knew that we had to do some work to our brick wood burning fireplace, and have been really swaying toward putting in a gas direct vent insert. When I looked up into the flu I was surprised to see that we don't have a damper AT ALL. The previous owners had removed it leaving us with a 1' x 2' opening going up into our flu. My question is, will the chimney balloon work for me if I want to convert my existing fire place into a direct vented gas log? -JD

A: Dear JD, Considering the outside temperature isn't getting any warmer at this time of year, I would suggest you get a Chimney Balloon in this fireplace very soon so you wont be loosing your interior heat up the flue.

It could be that the previous owner had a vented gas log in this fireplace when he lived there (he must have taken it with him) and that is why the damper was removed. Building code states that a vented gas log fireplace must have the metal damper removed or clipped open regardless if the fireplace is in use or not.

The reason for this code is to keep people with vented gas logs from accidentally asphyxiating the occupants of the home by burning the gas log with the damper closed. The side effect of this building code is wholesale heat and A/C loss 24/7 through the flue.

Many vented gas log owners opt to use a Chimney Balloon in the flue to stop the heat and A/C loss. If they accidentally light the gas log before manually removing the balloon it is designed to shrink and burst and still allow the fireplace gasses to escape. This saves the occupants of the home, but sacrifices the Chimney Balloon.

When you install a direct vent fireplace insert I suggest you have it vented through the wall and have the flue plugged with a Chimney Balloon. Even if you decide to wait on upgrading the fireplace get that balloon in right away. If you decide to vent the new direct vent gas fireplace up the chimney, you will still have to work out some way to plug the rest of the flue around the vent pipes. - Jason

Can I seal my flue tight when using a non-vented gel burner log?

Q: I have a small, 100 year old fireplace that I do not use because the chimney is unlined and I can't afford to get it lined. There's no damper either. I have decided to put a fake log and an alcohol gel burner (ventless) in there for the ambiance and a small bit of extra heat. I intend to block off the top of the firebox with a steel plate and fireplace caulk. This should keep air from going up the chimney, but will not stop heat loss via radiation.

Do you think, if I installed a chimney balloon 4 to 6 feet above the metal plate, it would survive? These gel burners put out 3000 BTU per hour per can, and I might at times burn 3 cans at a time, for a total 9000 BTU per hour. The flames would not be high enough to touch the metal plate. Thanks, ADH

A: Dear ADH, The Chimney Balloon will trigger its release at about 180-200 degrees Fahrenheit. I am certain it will only take about 5 minutes for a couple of rocket fuel... I mean... gel fuel, canisters to get the flue temp on the other side of your metal plate up to that temp. That metal will conduct pretty well once you get it cooking.

I do want to give you a fair warning about the adaptations you are planning to do to your fireplace. This type of DIY fireplace project is what makes home insurance agents get ulcers. When you self seal a fireplace flue with a metal plate in order to save heat you are definitely taking your chances. The heat will spill around the lintel of your fireplace and go right up the mantel and facing wall. When your mantel clock bursts into flames and your Hummel figurines neatly arranged on the mantel melt from the spilled heat it will be a bit too late to correct the error.

I'm being tongue-in-cheek here, but seriously, altering an existing fireplace to trap heat is not a DIY kind of thing. I don't even know many fireplace professionals that will try it (unless it is at their in-laws). You might luck out and fix it up just right, and you might create a real safety risk. - Jason

Q: Jason, Thanks for you input about the chimney pillow and the concern about the fireplace adaptation. Before planning to do all this, I consulted specs from several manufacturers for ventless gas logs placed in existing fireplaces.

According to specs, ventless gas logs for this size fireplace, burned with the damper closed, can safely run at considerably more than 9000 BTU given the distance between the top of this particular fireplace opening (which has a hood) and the mantel. The metal plate will be in the same place a damper would be-- if there was one-- and dampers are metal, so I don't see the problem. (It will only be touching firebrick and will be several inches back from the fireplace opening, also.)

A number of people in old houses here have had their fireplaces blocked off and big, honking gas logs installed without incident-- seems to be standard practice around here anyway.

A: Dear ADH, I am very relieved to hear you researched it fully first, and it sounds like you covered your bases. Good luck with your fireplace project. - Jason

My Majestic brand direct vent fireplace is letting in cold air, what can I do?

Q: Jason, I have a vented Majestic fireplace. We do not use it, but it is letting tons of cold air into my house. The vent on the outside of the house doesn't seem to have any sort of damper on it whatsoever... so closing that is not an option. Right now we have the gas turned off & a blanket over it.

Would a Chimney Balloon help with this? How exactly would we get in to measure the hole? How do we get into the part that has the gas logs?- CG

A: Dear CG, By a few hints in your question, I am assuming that you have a direct vent fireplace not a gas log fireplace. You say "vent to the outside", does that mean the vent is a PVC pipe that goes directly through the exterior wall, not out the roof like a chimney?

If it vents through the wall you definitely have a direct vent fireplace.

The good news is, that direct vent gas fireplaces (unlike vented gas logs) generate heat efficiently when running. The bad news is, if the fireplace installer does not take care to insulate the fireplace install correctly it will let in a great deal of cold air when dormant.

If you have not had the original installer over to look at the problem I would try that first. If they stonewall you about it, call an insulation contractor that is forward thinking enough to work with closed cell foam.

You see, a fireplace installer will sometimes slap in a fireplace and think "good enough" but an insulation contractor has a different way of thinking. He will look over an install and consider how it effects the homes envelope and how he can make an install both safe and tight.

I'm sorry but a chimney balloon will not help you on a direct vent fireplace since the firebox is a sealed unit and you can't gain access to the vent flue and that vent flue is just a small pipe through the wall anyway. - Jason

Can I burn candles in my fireplace with a Chimney Balloon installed?

Q: I have a very old fireplace that is not operational and I use strictly for decoration. the flue in masonry and unlined. It was capped/closed at the top by the previous owners. I want to get a Chimney Balloon because I suspect that there is still heat loss through this flue given the age of the house--120+ years old.

However, I also like to burn decorative candles in the fireplace from time to time. Will the Chimney balloon work in this case or do I need to find something more fireproof? how much space should I allow between the candles and the Chimney Balloon. Thanks.- PH

A: A Chimney Balloon will help this capped chimney retain more heat by closing it low in the flue and tight. But you don't want it too close to the flame because it is designed to melt and release at a temperature of 180-230 degrees Fahrenheit.

If you keep the candles at least 3 feet away from the balloon and keep the wicks trimmed you should not have a problem. But if you have 12 candles raging in the fireplace with long smokey flames you could easily get up to the 180-230 Degree flash point.

Personally, I burn a 6 candle candelabra in my fireplace in the summer and I have a 9x9 Chimney Balloon installed about 3 feet above them...and i have never had a problem. - Jason

Can I plug a leftover chimney pipe in my wall with a Chimney Balloon, or should I use fiberglass?

Q: Dear Jason, I have a chimney which used to be used for a wood burning stove.  We removed the stove and wish to stop the cold air entering the house through the round chimney hole that is left.  Basically, there is a hole in the wall of our house that leads to the chimney and I just have it covered with a loose fitting metal cover.  Can your chimney pillow work in this situation? 

My husband was thinking of stuffing the chimney hole in the wall with fiberglass, would this work? - EE

A: Dear EE,  I am willing to bet you will find the diameter of that pipe to be 9" or less so a 9x9 Chimney Balloon will work well. If it is over 9" then you may need to go with a 12x12 Chimney Balloon.

If you call in your order we can adapt a 9x9 for you to have an extra short 3" handle on it, so it is easier to put in the chimney pipe and clear the wall.

You will find the Chimney Balloon will air seal and insulate in one shot better than the fiberglass plug. The basement is generally the location that the home will draw in air the strongest at due to the air stack effect in the home. The air will pass right through a fiberglass plug, but it wont be able to draw through a Chimney Balloon. - Jason

How do I seal a zero clearance Majestic brand fireplace so it isnt so drafty?

Q: We have a zero clearance fireplace manufactured by Majestic. I've tried another fireplace product which is supposed to fit at the top of the firebox to cover the flue. It did not fit properly because there are two metal "fins" that extend downward from the top of the firebox on either side of the flue. Does your product work with zero clearance fireplaces?

P.S. Was glad to read the question and answer about burning candles while the Chimney Balloon is in use. Thanks for the info!- TP

A: Dear TP, The Chimney Balloon does work with Zero Clearance fireplaces like the Majestic model you are referring to. As a matter of fact I am using a 9x9 Chimney Balloon in a Majestic Zero clearance fireplace in my own living room.

Since the Chimney Balloon is installed up into the flue you can get it up past these fins and inflate it into place. I would recommend though that you use an HEK extender with your Chimney Balloon, since the fins are so obtrusive in this model fireplace. Give us an email or a call if you have any more questions. - Jason

Followup: Just wanted to follow up to say that the 9x9 balloon fit my zero clearance perfectly. This has made a major difference in the drafts attributable to our fireplace. Thanks for a terrific product!- TP

Reply: Hi TP, Thank you for checking back with us. Im glad everything worked out so well for your application. It is a relatively simple fix with a Chimney Balloon.

The install location is a major difference between the Chimney Balloon and the competing Draftstopper product when you compare the two. The Chimney Balloon installs in the flue away from the damper hardware and it expands wall to wall providing a superior seal. - Jason

Where do I put a Chimney Balloon if all the flue walls slant?

 Q: Inside my fireplace about 29" up from above the opening is the damper. Just below the damper and each of the four sides or slit type openings. I do not know why. Maybe for air? I just saw the picture from SH and that is what mine likes like except all 4 sides slant in. It is about 10x10 at the damper. - KT

A: Dear KT, Since the sides slant on all 4 sides we will have to do the install high or low. We can use an HEK extender and a small 12x12 Chimney Balloon to install above the damper, or we can use the ledge that is generally just on the lintel and install a larger 36x15 Chimney Balloon. The lower install is easier but the balloon may be slightly visible from the room. _ Jason

Very small flue with a smoke coming in the upstairs fireplace when we burn in the downstairs fireplace.

Q: I have a house built in 1870, and the flue I would like to seal appears to be very narrow, somewhat jagged, and irregular in shape. The best I can tell, the opening appears to be about 6 inches deep, and 12 inches wide. Which size would be best for me? And do you think there is a wider opening further up the chimney? If so, would I be able to push the balloon up there and then inflate it??

Also, like Maureen in the previous post, I have a smoke situation and am hoping your product will help. We have multiple fireplaces, and when I burn a fire in the living room downstairs, smoke enters my son's bedroom upstairs. They are on the same chimney. This started happening after we added a chimney cap to keep birds and animals out. The guy who did the work came back, and claims he sealed the flue heading into the boy's bedroom. But we had one more fire at the end of last season and still smelled smoke in his room during the fire downstairs. Please advise... - JW

A: Dear JW, Well, to answer your first question... I would go with a 9x15 Chimney Balloon for that size hole to plug. It does not matter much if the hole is jagged and rough in shape as long as the hole is not any larger than 9"x15" and has roughly parallel walls on at least 2 sides.

On your smoke crossover question...Yes, the Chimney Balloon will give you a very tight seal on your unused chimney so the smoke smell will not be sucked back into the home. Im sure your Chimney sweep gave it a good try to seal it up, but there is no way to get as tight of a seal as a Chimney Balloon will offer. Even a fiberglass bat plug will allow odor back in through it. - Jason