Venting Into a Fireplace

Many people may wish to convert an existing fireplace to heater use. Usually, safe connection of stovepipe to a masonry chimney requires more effort than connection to a prefabricated chim- ney. The fireplace must be tightly closed and sealed at the damper in the flue. Good sealants are high-temperature caulking, ceramic wool, and furnace cement. Always remember to inspect the masonry chimney and fireplace. If necessary, clean the flue and smoke shelf before beginning your installation. Install the heater into the fire- place so that the system can be dismantled for cleaning and inspection.

Before deciding to convert your fireplace, keep in mind that some fireplaces and existing chimneys are unsafe. They must be structurally sound, and the flue liner must be in good condition. Do not use a chimney if it is unlined (should have a fire clay tile liner to protect brickwork). Have it relined professionally. Clearances to combustibles are explained in the previous section on masonry chimneys. If you have any questions regarding the condition of the chimney, consult a qualified engineer, competent mason, or knowledgeable inspector.

Many prefabricated fireplaces fall into the "zero- clearance fireplace" category. This is a factory- built metal fireplace with multilayered construc- tion. It is designed to provide enough insulation and/or air cooling so that the base, back and sides can be safely placed in direct contact with com- bustible floors and walls. Although many prefab- ricated fireplaces have been tested by nationally recognized organizations for use as fireplaces, they have not been tested to accept heaters. In fact, their use as such may void the manufacturer's warranty.

Steel-lined fireplaces, on the other hand, can be used with heaters. These units use a 1/4-inch firebox liner and an air chamber in connection with 8 inches of masonry to meet code. They contain all the essential parts of a fireplace, fire- box, damper, throat, smoke shelf, and smoke chamber. Many of them look exactly like a ma- sonry fireplace and must be checked closely for above requirements before installing a wood heater into them.

Another method frequently used by some people is to vent the heater directly into the fireplace. This does not meet code since the heater is being vented into another appliance - the fireplace. This method should not be attempted because com- bustion products will deposit and build up in the firebox or fireplace. Be certain not to install a hazard in your house. You will void your warranty with this installation.

CAUTION:

NOT ALL FIREPLACES ARE

SUITABLE FOR INSTALLATION

OF A WOOD HEATER.