To state again, a pre-fabricated fireplace system is also known as a "zero-clearance" fireplace. This is a fireplace made from a kit, that does not require any masonry. The components can be placed very close to combustibles without catching them on fire. These systems are common in apartment complexes, as well as single-family Dwellings. In the trade, we use round brushes that are soft to clean the flues, which are round metal piping. Over the last 24 years I have had possibly 5 customers that had the operating manual for the system. There is a right way (and a wrong way) to use these systems. Stay tuned for more data on operating these systems.
This pre-fab fireplace needs to be replaced. The refractory panels inside the firebox are cracked, the doors do not operated smoothly. The refractory panels inside the firebox are cracked, and the sliding fire screens are bent and do not slide; the glass doors do not close easily.
Here is a top view of the flue pipe of the system. Notice that there a pipes within pipes. This is what makes the system "zero clearance" which means the parts of the system can be installed within one inch of combustible materials. The air space between the pipes creates buffer zones of multiple spaces of air that rise and vent out the top.
When a system has been over-fired, these pipes can buckle and separate ( The pipes are put together in sections). Usually you cannot disconnect the sections once they have been locked together (twist-locked). This is safety design. When pipes buckle and warp they need to be replaced. Many manufacturers have since gone out of business, so getting parts is almost impossible. Adding after market parts will void the UL listing of the system. The bottom line is that the whole system needs to be replaced.
Here is a system that was over-fired (notice the holes on the top of the rain cap.) The flat, rusted rectangular cover is a chase cover. The chase is a wood box that the chimney pipe travels through. Chase covers can be replaced easily.
Here is a new unit being installed into the wall (rear view.)
Outside view of a pre-fabricated fireplace installed in a wall.
The first order of business is to determine if your fireplace is prefab or masonry. You can identify which type of fireplace you have by looking up with a flashlight toward the damper area from inside the home – wear safety glasses to avoid dust and particles! A factory-built fireplace will have a round damper and a round pipe, usually 7-11” in internal diameter. The damper plate on a masonry fireplace is usually rectangular, and approx. 6” x 24”. You may also be able to ID your fireplace by looking at the exterior of your home. A masonry fireplace will should have an orange clay liner, which is often visible at the chimney top – from outside the home. The two pictures show a typical prefab fireplace inside box and cap/termination. Another hint is to look at the outdoor enclosure around your fireplace and chimney. If it is covered with siding like the rest of the home, you almost definitely have a prefab. If, on the other hand, the exterior is solid brick which extends down to the ground, it is probably a masonry chimney. Another hint is the presence of large visible louvers and black metal facing on the front of the fireplace opening – this usually means a prefab. If in doubt, have a pro check it out for you – they can also advise you on the safety aspect of any upgrades you may have planned. The panels inside of the firebox are called refractory panels. These get cracked and beat up by heavy pieces of firewood being thrown (as opposed to gently placed…) into the firebox. They can also get cracked by over-firing of the system (building a fire that is too large for the system to handle. Refractory panels can be replaced. A damper can be replaced with a damper that is mounted on top of the smoke stack. The chimney cap on top of the smoke stack can be replaced. But when should the entire system be replaced? Stay tuned.