How to Install a Fireplace Insert | Ask This Old House

In this video, This Old House plumbing and heating expert Richard Trethewey helps a homeowner supplement their living room heat by installing a wood-burning insert in their existing fireplace.

Richard Trethewey helps a family deal with a cold addition. The family’s living room was added to the home in the 1980s and only has electric heat to condition it, and would like to use the fireplace in the adjoining room to spread some heat. Once Richard explains how inefficient a fireplace can be, he solves the family’s issue by having a wood-burning insert installed in the fireplace.

A homeowner’s living room needs supplemental heat, and plumbing and heating expert Richard Trethewey knows how to use a fireplace in an adjoining room. The problem is that fireplaces themselves are unbelievably inefficient. While they do emit some radiant heat, they cause a draft that pulls the heated air from the rest of the home and sends it up the chimney.

A better option is a wood-burning fireplace insert, which emits radiant heat and forced hot air, while also preventing warm air from the home escaping. Richard helps the homeowner come up with this solution and then finds a local pro for the installation.

Where to find it?
Richard Trethewey helps a homeowner troubleshoot how to supplement heating their home by using their fireplace. Richard explains fireplace convection, why it’s not an efficient source to heat the home, and why a wood burning insert is a great option for the homeowner. After, a team of installers install a stainless-steel liner and wood burning fireplace insert.

Richard does a demonstration showcasing how fireplace convection works.

The fireplace insert works by:
• Pulling air from the room into the lower chamber.
• Air circulates behind the firebox, picking up the heat. From there, a fan pushes the heated air back out of the front facing vent above the fire.
• The heat from the central burner also emits more radiant heat from the face of the insert, back into the room.
• Combustion fumes and smoke vent out of the top of the insert through an installed chimney liner.
• The insert works as a seal, so even if there’s no fire burning, there are no drafts.

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From the makers of This Old House, America’s first and most trusted home improvement show, Ask This Old House answers the steady stream of home improvement questions asked by viewers across the United States. Covering topics from landscaping to electrical to HVAC and plumbing to painting and more. Ask This Old House features the experts from This Old House, including general contractor Tom Silva, plumbing and heating expert Richard Trethewey, landscape contractor Jenn Nawada, master carpenter Norm Abram, and host Kevin O’Connor. ASK This Old House helps you protect and preserve your greatest investment—your home.

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How to Install a Fireplace Insert | Ask This Old House

[AStanton]

We installed a wood stove insert 16 years ago. Best home improvement you can make, especially if you live in a cold climate. It's like having a back up furnace in case the house's furnace dies.

[ThierryC]

We installed a wood insert in our open fireplace after 2 winters in the house we just bought. The fireplace was literally burning the wood way too fast and smoke would always sneak in the living area, not to mention the smell during hot humid summers. The best investment ever we did with the wood insert, it burns longer, redistribute a lot of heat with its dual combustion feature and it does not smell smoke in the house at all even during summer time. I just added some insulation between the plate and the rocks around the fireplace opening to keep more heat in the house and completely remove any creosote smell.

[ginacirelli]

I had a Blaze King Sirocco insert installed into my 1939 Heatilator fireplace about 3 years ago and I love it! The install was a real challenge because the top of the old heavy steel firebox had to be cut through to connect the insert into a new steel liner.

[edmuboro]

Works like a charm! Set it on 2 and it holds 68 degrees whether it is 60 or 16 degrees outside. Good value!

[samspeaks]

Nice insight Richard. I have a insert that was installed when we built our home. The difference is its a posi-preasure insert. It has three intakes from the outside. Two feed the fire and one has a one horse power blower. The blower pulls air in that flows over the firebox and blows hot air into the house. Have in blower create a positive air pressure in the house and if we have any air leaks in the windows, doors, etc, the air pushes the air outward and doesn't allow cold air in. It also has a catalytic converter for the fire to reduce pollution.

[I-Teee]

After quotes of $6-8000, I had an Osburn unit purchased and installed for $3500. Payback including buying wood was 2.5 years for me vs home heating oil. And that was when oil was $2.10 a gallon. I went from using around 1, 000gal of oil per winter to 150gal, and my house is always nice and warm. I load the firebox three times a day and it runs 24/7 in the winter.

[brucemitchell]

We just had a direct vent gas insert installed into our fireplace. Best investment in our house and we absolutely love the convenience of gas fireplace, and it will work if we lose power.

[lcee]

We have an insert very much the same. Really helps with the heat! (Even when the power goes out)

[GKALLIO]

I liked your incense smoke demo. Nice touch! Now, the system should have been sealed with a blocking plate near the removed damper and/or at the top of the chimney to eliminate air infiltration. I wish this video addressed that. Also, it would be prudent to seal the interface between the backing plate and brick in case there are other unforeseen leaks in the system.

[gradywray]

We had one of these installed at my folks house and man does it make a difference. No soot inside and it really heats the place up!

[dpacheco]

Installed one last year, excellent purchase, furnace never runs when the insert is fired up...

[TENTHIRTYONE]

Just what I was looking to learn about on this 90 degree day in June.

[jamesfetherston]

One of the first improvements we made to our home after purchase was a fireplace insert, and a ceiling fan. Makes a huge difference.

[seang]

If we ever go to mars they need to send the ask this old house crew. I swear these people can do anything.

[liammcgough]

I wish that I saw this video before. I used to own a Levittown ranch which had a fire place that was open on the kitchen and living room side. I could only use the fire place in the fall or the house would loose to much heat like in the winter. I don't ever recall this old house doing a program involving a Levittown home. That would be pretty cool and helpful to Levittown home owners.

[kevinremsen]

There’s nothing like wood heat. I had a wood stove insert at our old house and I really miss it.

[AdamOmidpanah]

Honestly, why is the liner needed if you have a functional brick chimney? I have clay tile liners and a double bricked smoke shelf so there are a few pinch points where a liner can't fit down my chimney. However, the clay tile was meant to be precisely that - a liner - which focuses the toxic gasses on exiting the chimney through the top by narrowing its diameter, increasing the heat shield, and adding layers of insulation.

[TheESC]

Will the stove/insert operate as intended even if there is a power outage and the intake fan isn’t working? Also, what is the life span of the intake fan and blowers and are they easy/cheap to replace?

[SignorLuigi]

Why not use outside air for the combustion air so no conditioned inside air is wasted? Just because of the initial installation cost? How long would it take to recoup that cost in home heating energy savings? Wouldn't the stove insert also be a little less "drafty" if it draws air directly from outside?

[victororozco]

Living in California I never heard of stuff like this but that’s smart, only heard of radiants