There is one other kind of installation that meets building code, called a direct connect. We do not install direct connect installations, and the National Fireplace Institute does not allow them. We don’t feel that direct connects are safe, and you can learn why here. Please note that it is not legal, and very dangerous, to install a stove or insert into a fireplace without either a direct connect or a full liner – this is referred to as a slammer. A “slammer” is when an insert or a stove Is pushed into the fireplace without any liner or pipe coming out of the top. This kind of installation produces heavy deposits of third-degree creosote on and around the insert, which can easily ignite and cause damage to the insert and chimney, or even start a house fire.