Unconditional guarantee: if for any reason you are not completely satisfied by your purchase, simply return the product with proof of purchase for a replacement or refund, whichever you prefer. Your firelog has been designed for use in regular brick fireplaces, heavy gauge metal- lined masonry fireplaces, or manufactured fireplaces and fireplace inserts listed by underwriters' laboratories, ul inc. Or warnock hersey having minimum burning areas of 640 sq.in. (4129 cm.sq.). Use in smaller appliances may be hazardous. Many factors affect the operation of your fireplace. A properly installed and maintained fireplace and chimney will dramatically reduce the likelihood of combustion by-products entering your home. *In may, 1988, canmet, the research laboratories of energy, mines and resources canada, conducted an evaluation of firelogs with clean-burn and natural wood. The report concluded, "...firelogs with clean-burn can be expected to significantly reduce: 1. creosote deposits in the fireplace chimney. 2. particulate emission into the air. 3. carbon monoxide emissions into the air." +Burn times may vary with fireplace design and draft. If your fireplace is functioning properly, emissions of this product should be vented outdoors. A properly installed and maintained fireplace and chimney will dramatically reduce the likelihood of combustion by products entering your home. An inadequate air supply or a downdraft could cause a fireplace malfunction. If you suspect that your unit is not functioning properly, a qualified contractor should be consulted. Burns cleaner than wood.* Burns up to 2 hours.+ Wood-wax fire logs. Unconditional guarantee.