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-> Also read our article “Is it Time to Replace Your Wood burning Prefabricated Fireplace?

The fireplace industry considers prefab wood burning fireplaces to have a life expectancy of 10-30 years. Like other household appliances, they just don’t last forever. The good news is that there are many options for upgrading to a better system when it comes time for replacement.

Keep in mind that the fireplace must be removed from either the front facing wall (inside the house), or from the rear.

  • Removal from the rear is usually the easiest method, especially when the fireplace is installed against an exterior wall and the framed chase has been covered by siding. We remove the siding and underlayment to gain access to the inside of the chase. The chimney is normally removed from the top and sometimes the chase is large enough to actually get inside to assist in unscrewing and disconnecting the chimney sections, but it’s rarely this “easy”.
  • Removal from the front of the fireplace opening commonly involves removal of the facing material (slate, marble, tile, etc.) and the mantel, resulting in a bigger mess, greater expense and more work overall. However, if you’ve always wanted a different style – say tiles or granite instead of the old slate or a new mantel — then this is the time to plan out your new look!
  • When it comes time to choose a new fireplace model to install, consider the options available to you. Commonly the original model was a “builder grade” appliance, an inexpensive model wood burning fireplace with minimal features.

New, high-efficiency wood burning prefabs that are manufactured with quality metal, tightly fitting glass doors are available. They are energy efficient combustion designs that provide burn times and heat output comparable to a wood stove. If you still enjoy wood fires then why not consider a high-efficiency model that can help provide substantial heat when needed? This classification of wood burning fireplaces also uses upgraded chimney systems meant to withstand higher temperatures.

White Gas Log Fireplace - Bless Your Hearth - Laurens SC

Gas Fireplaces provide the beauty of real flames without the work and mess associated with burning firewood. Like wood burning fireplaces, gas models are classified as either “decorative” or “heater rated”. Heater rated models have a glass window instead of an open fire, protecting against contact with open flame. Most models also work during power outages, providing excellent backup emergency heat if you’ve chosen a heater rated
fireplace. Unlike wood burning fireplaces where the type, condition or amount of wood greatly affects heat output, gas fireplaces are designed to
withstand a maximum constant heat production so over firing isn’t a concern with this class of appliance. Heater rated gas fireplaces use the gas
more efficiently and transfer that heat to your living space, providing substantial heat when desired. Better models also offer thermostat controls that modulate the flame to adjust the heat output so you’re never too warm or too cold. Direct vent models, which use outdoor air for combustion, provide versatile installation and venting options where a wood burner couldn’t be used such as venting horizontally through an exterior wall.

The expense and labor involved in a prefab fireplace replacement may lead you to consider a conversion or alteration of your fireplace, thinking that “If it’s not safe to burn wood, I’ll just convert to gas.” That’s a great idea, but you can’t take a shortcut here.

CAUTION: ABSOLUTELY DO NOT PUT GAS LOGS into a damaged or deteriorated wood burning fireplace. Vented gas logs require the fireplace and chimney to be suitable for use with wood. If it’s not safe to burn wood, it’s NOT SAFE to use with gas logs, either!

Contrary to popular opinion, ventless (vent-free, unvented) gas logs are far worse! They are designed to allow you to close the damper, keeping the heat produced concentrated in the fireplace. While this may feel like a good idea it’s making more heat right where it’s more likely to cause a problem including pyrolysis of the adjacent wood framing within the wall.

An ELECTRIC INSERT is a very inexpensive option. An electric fireplace is uniquely capable of offering you flames with no heat so you can have a romantic fire in the summer, or use with the heater option when the weather turns chilly. This at least provides you the ambiance of a “fire” with no need to tear anything out. These are surprisingly realistic looking and is an option more and more customers have chosen in recent years. Blue Sky Chimney Sweeps|Bless Your Hearth is happy to help guide you through the options for repairing, replacing or possibly just upgrading your prefabricated wood burning fireplace!

Blue Sky Chimney Sweeps|Bless Your Hearth is happy to help guide you through the options for repairing, replacing or possibly just upgrading your prefabricated wood burning fireplace!-*+


What we’ve learned…..

Vent-free /Unvented gas logs usually require the damper to be closed.  Some folks opt to just seal the throat of their fireplaces or the tops of their chimneys when these gas log systems are installed.  Vent-free or unvented gas log appliances are somewhat controversial.  There are some issues that have become evident in the last few years.

Vent Free Unvented Gas Logs - Spartansburg SC - Blue Sky Chimney Sweep


There are several scenarios that can cause the system to emit low levels of carbon monoxide.

  • Animal dander, pet hair, or dust on the burner
  • flame impingement from the logs being positioned incorrectly
  • air movement across burner

Any of these circumstances can cause the logs to burn at less than 100% efficiency and emit carbon monoxide.  Since these systems are sometimes categorized as “room-vented” appliances, the issues they raise can cause concern.

  • These low levels of carbon monoxide emission usually will not trigger your carbon monoxide detector, but are considered a health hazard.
  • The instructions on the logs say not to install in a bedroom or to use if you are pregnant, have emphysema, or other respiratory problems.

If they are not healthy under these listed circumstances, perhaps there is cause for concern across the board.


There is a concern about heat buildup in the firebox.  Fireplaces are designed to flush most heat up into the flue.  When logs are burned with the damper in the closed position or with the throat area completely sealed off, most of the heat is retained in the firebox.  This causes the walls of the firebox or the breast area of the fireplace to become hotter than normal.  Heat is then transferred through the firebox walls and into the wall cavity surrounding the fireplace.

If the builder did not observe proper clearances, or if framing lumber is in contact with the shell of the fireplace, pyrolization will occur.  When the wood repeatedly heats and cools as the logs are used, this causes the flash point or ignition temperature of the wood to lower.  Numerous home fires have been documented as starting in the walls, either next to or directly above the fireplace opening behind the mantle.


Many times the incentive to get vent free gas logs is to produce more heat for the living area especially in the event of a power outage.  Under these circumstances, the gas appliance may be operated for many hours without interruption.  This can be a problem because many manufacturers’ instructions stipulate a limited operation time.  Their specified time frame for operation insures that the levels of carbon monoxide that are emitted in the home are within the parameters considered nontoxic.  If those time frames are exceeded, then the levels of emissions in the home may exceed safety standards.

Because of these concerns, vent-free gas logs are against code in some states (including California, Colorado, Wisconsin, Massachusetts) and the entire country of Canada.  There are several websites that deal with carbon monoxide including and  

Our Recommendation

Our recommendation is to install vented or direct vent gas appliances. If vent free or unvented are chosen, we recommend a dual listed log set (one that can be operated with damper either open or closed) when installed in a wood burning fireplace/chimney.  If strictly vent-free/unvented are installed, we encourage operators to be familiar with manufacturer’s operating instructions and follow them strictly for safest operation and best results.  In all cases, we recommend that all gas appliances are regularly maintained and that carbon monoxide detectors are installed and checked regularly to make sure they are working.

Blue Sky Chimney Sweeps | Bless Your Hearth offers installation and service for gas logs, stoves, inserts and fireplaces.