Many homes use a wood, gas, or electric stove or fireplace for primary or secondary heat. Others use them for ambiance. Fireplaces and stoves are relatively trouble free and many are efficient heat sources. Here's how the Fix-It Club takes care of fireplaces.

How Does It Work?

An open wood fireplace consists of a hearth where wood is burned for heat and a chimney flue for expelling the smoke. Because heat can be lost with the smoke, a fireplace insert is often installed to increase heat retention. A freestanding wood stove, pellet stove, and gas stove also decorates and warms a home and requires some of the same maintenance and repair as a fireplace. (The terms "stove" and "fireplace" typically are used interchangeably.)

All fireplaces have the same two requirements: regulated air to feed the fire and a means of expelling smoke and fumes. A shuttered damper in the chimney provides an exit for smoke as well as creates an updraft that draws fresh air to the fire. Many new fireplace designs also use outside air intake vents under the fireplace so as not to draw warm air from the room. Gas fireplaces often have an inlet/outlet vent that expels fumes through a duct in an outside wall while drawing in fresh air.

Pellet stoves burn pellets made from sawdust and mill shavings; the pellets are loaded into a hopper at the top or front of the stove and delivered to the combustion chamber at a controlled rate by a motorized auger. Combustion air, blown into the chamber, develops superheated air. Room air is drawn across the heat exchanger by a fan, heated, and then returned to the room. Residual combustion gasses are vented outside, normally through a 3-inch flue that exits out the unit's back or top.

Fix-It Tip

Creosote, a by-product of burning wood, isn't the problem it used to be because today's fireplaces and wood stoves are much more efficient and burn hotter, which decreases the amount of creosote produced. As a result, creosote may not get a chance to build up inside and become a fire hazard. Even so, inspect your fireplace and chimney at least once a year for a flaky black creosote buildup.

What Can Go Wrong?

Components of a typical fireplace.

A chimney will need cleaning. A fire may burn poorly and send smoke back into the room. A stove's door gasket may wear out or come loose. A stove connector may corrode. Bricks or mortar may be damaged. The igniter of a gas stove may fail.

Fix-It Tip

Make a bed for a better fire. Keep a half-inch bed of ash in the fireplace after cleaning as an insulator to prevent heat from being absorbed into the hearth.