The primary disadvantage of a ventless fireplace is that it doesn’t have an exterior venting system. This means that the byproducts from combustion are emitted into your home, which raises some safety concerns. In addition, ventless gas fireplaces produce moisture as they burn—and if there’s no ventilation, you could end up with a mold problem.

A spark arrestor is a simple metal mesh device that prevents flammable particles from escaping from a combustion source and causing a fire. You typically find these attached to gas or diesel engines on things like cars, generators, and garden tools (lawnmowers, chainsaws, etc.). Fireplace or wood-burning stove chimneys also have spark arrestors attached to or sitting under the chimney cap to capture burning embers.

No, you should never leave a fireplace burning overnight or unattended during the day. While fireplaces are made to contain fires, fires can and do spread from fireplaces, so it’s crucial that you’re there to monitor them and put them out if needed. If you’re worried about putting out a fire before bed, stop feeding it fuel long before bedtime and actively put out the fire using your poker, a shovel, and some baking soda.

Signs that your dryer is about to catch fire include a burning smell or the dryer and the clothes getting hotter than usual. If this happens, turn the dryer off immediately and call a repair professional. Another less urgent sign is that your clothes are taking longer to dry than normal. If this is the case, check the lint trap, vent, and duct to make sure they are all clean. If they are, you may need to call a pro to find the source of the issue.