Fireplace inserts: the cure for cold fireplaces

Jotul Wood Inserts are used to convert masonry fireplaces, which are inefficient and polluting, into effective heating systems.


A Jotul cast iron wood fireplace insert is like a wood stove that has been modified by its manufacturer to fit within the firebox of a masonry fireplace. Jotul wood inserts are used to convert masonry fireplaces, which are inefficient and polluting, into effective heating systems. An insert consists of a firebox surrounded by a steel shell. Air from the room flows between the firebox and shell to be warmed.

The outer shell ensures that most of the heat from the firebox is delivered to the room instead of being released into the masonry structure. A decorative faceplate covers the space between the insert body and the fireplace opening.

Since 1991, the Canadian wood burning installation code has required that a stainless steel chimney liner be installed from the insert flue collar to the top of the chimney (Direct connects are still permitted in the United States). The code permits alterations to the fireplace to let the installer create a clear route for the liner as it passes through the throat and smoke chamber of the original fireplace. For this reason, a good insert installation should be considered permanent. Installed correctly, the wood insert should not need to be removed from the fireplace for many years because the liner and all the hardware supporting it is corrosion-resistant stainless steel.

Where the liner passes through the fireplace throat (the damper, smoke shelf area), it should be sealed to the masonry, either stuffed with mineral wool (rockwool) or with a sheet metal plate. A good seal in this location prevents cold, smelly air around the liner from migrating into the room.

This improvement in the design of insert installations has improved their performance to the extent that today's best fireplace inserts can be almost as efficient as free-standing wood stoves. If you already have an insert installed in a masonry fireplace, the addition of a stainless steel chimney liner can improve performance.

Full liners for inserts and hearthmounts have become among the most trouble-free of all wood heating installations. This is because the liner runs almost straight up from the insert flue collar, which is the most desirable arrangement for reliable draft. Cleaning the flue is a simple matter of removing the cap and running a brush down to the insert. Any deposits are cleaned from the firebox by removing the baffle. The reliability of an insert installation depends on a perfect installation. If the liner connection at the insert flue collar is faulty, causing the liner to fail, the results can be very messy. Knowing all the ins and outs and pitfalls of insert installations is a job for professionals. Don't make the mistake of thinking that installing an insert is a simple matter of running a liner up the chimney. Contract with the most experienced Jotul insert installer you can find. You won't regret the small additional cost.


A hearthmount Jotul stove is an option to an insert for upgrading the performance of a masonry fireplace. Hearthmounts are wood stoves mounted in front of or inside the fireplace and vented through the fireplace throat. They should also be vented through a full liner that is continuous to the top of the chimney. Only certain wood stoves can be used as hearthmounts. The certification label and installation instructions indicate if the unit can be vented through a fireplace.