Converting Fireplace to a Wood Insert

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

ccrpm1617

New Member
Aug 10, 2022
3
19067
We have an old fireplace that we had inspected recently. To use as-is, we will need to reline the chimney and properly seal it. The inspector also said we could put in a wood insert as an alternative, which isn't that much more expensive. We would love to have a wood insert, but the issue we are having is that we have these vents (I believe Heatilator vents). There is no blower or electrical at the top. The bottom ones are too close to the opening for a wood insert to fit without interfering with them.

Considering that we are going to switch to a wood insert that is a closed system with its own flue, we are thinking about refacing the fireplace and covering the vents altogether to have a clean surface for the wood insert. The inspector said this wouldn't be a problem. Does anyone disagree with that?

This website seems to agree with him: https://www.fireplacedoorsonline.com/how-to-update-your-old-mark-series-heatilator-fireplace.html

[Hearth.com] Converting Fireplace to a Wood Insert
 
Last edited:
That's correct, they can be covered with the insert installation. However, a small insert's surround may not cover them. Or a custom surround could be used. And some inserts can be installed and look good with no surround.

What are the dimensions of the fireplace? How much area would the insert be heating? Will the insert just be heating a room area or a larger open area?
 
That's correct, they can be covered with the insert installation. However, a small insert's surround may not cover them. Or a custom surround could be used. And some inserts can be installed and look good with no surround.

What are the dimensions of the fireplace? How much area would the insert be heating? Will the insert just be heating a room area or a larger open area?
Thank you! Height-wise there is no issue. Our fireplace opening is 31 inches wide and the space between the two bottom vents (from inside edge to inside edge) is 41 inches wide. We are looking at either of the two models:

1. (broken link removed) - 42.75 inches wide with small surround
2. (broken link removed) - 44inches wide with Mead surround that we like, 43 inches wide with a more basic surround

Ideally we'd like to resurface the face of the fireplace, but we aren't sure on the style...maybe plaster or stone? I am a purist and would have loved to keep the original brick since it is in good shape, but considering the previous owners already painted it this awful color (it's more yellow in person) and we have the vents to fill, it makes more sense to reface in the future.

Is there any harm in filling the bottom vents and keeping the top ones in the meantime, while we use the insert? It's just that we don't necessarily need to fill the top ones until we do the refacing.

Thanks so much for your help and expertise!
 
Is there any harm in filling the bottom vents and keeping the top ones in the meantime, while we use the insert?
No harm there.

Internally, these are the same insert, just with a different door and surround treatment.
 
Last edited:
Welcome to the forums!

When I had the PE installed, my original plan was to totally cover the heatalator vents. They worked great when the FP was running, but I figured I'd be better off with them covered.

Fast forward, I never got around to doing the final cover, and you know what? Glad I didn't. I still have the grates, which need a good sanding and painting, but I'm not in a rush.

When the power goes out in the winter, and the insert fan is out of commission, those heatalator vents still kick in, and throw some serious heat. I was very surprised to find this out, to say the least.

I now regret the tile finish, shoulda kept the brick and done something with that.

My 2 cents, your mileage may vary ;)

[Hearth.com] Converting Fireplace to a Wood Insert[Hearth.com] Converting Fireplace to a Wood Insert[Hearth.com] Converting Fireplace to a Wood Insert
 
  • Like
Reactions: dafattkidd
Welcome to the forums!

When I had the PE installed, my original plan was to totally cover the heatalator vents. They worked great when the FP was running, but I figured I'd be better off with them covered.

Fast forward, I never got around to doing the final cover, and you know what? Glad I didn't. I still have the grates, which need a good sanding and painting, but I'm not in a rush.

When the power goes out in the winter, and the insert fan is out of commission, those heatalator vents still kick in, and throw some serious heat. I was very surprised to find this out, to say the least.

I now regret the tile finish, shoulda kept the brick and done something with that.

My 2 cents, your mileage may vary ;)

View attachment 297754View attachment 297755View attachment 297756
This is really helpful, and I love your insert! I appreciate you sharing your experience. It'd be interesting to see if we get the same effect with the top vents open only.
 
This is really helpful, and I love your insert! I appreciate you sharing your experience. It'd be interesting to see if we get the same effect with the top vents open only.
If that is the goal, they will convect better with both bottom and top vents left open.
 
  • Like
Reactions: Dix
If that is the goal, they will convect better with both bottom and top vents left open.

Agree, they pull the cooler air from the floor, and circulate to the tops.
 
I chose to close up the vents. See before and after pictures

The mortar was still a little wet at that point. Now that it's all the way dry you can't tell the difference
[Hearth.com] Converting Fireplace to a Wood Insert [Hearth.com] Converting Fireplace to a Wood Insert
 
Why do you guys want to close the vents? if anything you would think the heat gain from them would make it a no brainer to keep?

if u don't like "the look", why not replace the cheap vent covers with some nice iron covers.
 
Why do you guys want to close the vents? if anything you would think the heat gain from them would make it a no brainer to keep?

if u don't like "the look", why not replace the cheap vent covers with some nice iron covers.
The main reason is that I really didn't like the look, no matter what vent cover was on there, I wanted brick.
Secondly, and more importantly, when I cut out my heatform to fit my liner, you cut through the double wall of the heatform. Doing this connects the vents directly to the chimney. Even though there's a cap over the chimney, I still had cold air falling through those vents. There's lots of rockwool stuffed in there, but that doesn't make it airtight. IMO if it gets that hot back there, the brick will radiate that heat back in to the room
 
Why do you guys want to close the vents? if anything you would think the heat gain from them would make it a no brainer to keep?

if u don't like "the look", why not replace the cheap vent covers with some nice iron covers.
If it is a central chimney you might get a little heat gain. If it's on an exterior wall there will absolutely be a net loss. Not to mention air leakage out the chimney if you had to cut out to allow a liner to pass through. I always atleast stuff them with roxul if I install an insert
 
  • Like
Reactions: bigealta
The main reason is that I really didn't like the look, no matter what vent cover was on there, I wanted brick.
Secondly, and more importantly, when I cut out my heatform to fit my liner, you cut through the double wall of the heatform. Doing this connects the vents directly to the chimney. Even though there's a cap over the chimney, I still had cold air falling through those vents. There's lots of rockwool stuffed in there, but that doesn't make it airtight. IMO if it gets that hot back there, the brick will radiate that heat back in to the room
I usually stuff that cavity full after I cut out the firebox as well to help direct the heat into the room.
 
I usually stuff that cavity full after I cut out the firebox as well to help direct the heat into the room.
On an exterior chimney, how much insulation can you put behind the insert (space permitting). I don't have a blockoff plate now but plan to make one. I don't think I have any rockwool behind the insert right now, and figured that might be a good time to add some when I take the insert out to put the blockoff plate in
 
On an exterior chimney, how much insulation can you put behind the insert (space permitting). I don't have a blockoff plate now but plan to make one. I don't think I have any rockwool behind the insert right now, and figured that might be a good time to add some when I take the insert out to put the blockoff plate in
I don't like to have insulation touching the insert. Otherwise as much as you can get
 
  • Like
Reactions: vbu