Check the flue first
A stove burns more slowly than an open fire, with cooler exhaust, so it needs a well-sized, warm flue to draft well and stay clean. NFPA 211 recommends an inspection every year, with sweeping when deposits call for it. For a stove used as a main heat source, a mid-winter check is often worthwhile too, because a whole season of slow burns can build heavy deposits.
- Has the flue been swept since last winter?
- Is there a cap, and is its mesh clear?
- Does the connector pipe fit tightly, with no rust or gaps?
- Is the stove door gasket intact and the glass clean?
Burn dry wood
EPA guidance says wood burns best at a moisture content below 20 percent and recommends seasoning it for at least six months, stored outdoors off the ground with only the top covered. It also recommends testing wood with a moisture meter. Wet wood is the single biggest cause of creosote: energy goes into boiling off water, the fire burns cool, and the smoke condenses in the flue.
Run the stove hot enough
- Start with small, dry kindling and plenty of air until the fire is burning strongly.
- Add wood in smaller loads more often rather than packing the firebox.
- After loading, leave the air open long enough for the new wood to catch before turning it down.
- If the glass blackens quickly or the smoke from the top is thick and dark, the fire is too cool.
Long overnight smolders are convenient but are the classic way to build glazed creosote, the hardest kind to remove.
Never burn these
EPA lists household trash, cardboard, plastics and colored inks; coated, painted or pressure-treated wood; driftwood, plywood, particle board and glued wood; and wet, rotted, diseased or moldy wood among the things not to burn. Driftwood deserves special mention near the coast: it is tempting to gather, but it is on EPA’s list. EPA also says never to start a fire with gasoline, kerosene or charcoal starter.
Installing a new stove or insert
If you are adding a stove, start with the chimney. A Level 2 inspection, which NFPA 211 calls for when an appliance is added or changed, shows the flue’s size and condition. Most inserts, and many stoves on masonry chimneys, need a full-height liner sized to the stove’s outlet, as the stove’s installation instructions specify.
Check the stove’s required clearances to walls, mantels and trim and its floor protection before you buy, and look for the EPA certification label. Most towns require a permit; Acushnet’s Building Department, for example, lists wood and pellet stove permits among its services. Ask your town before installation.
Pellet stoves and inserts
Pellet stoves work differently from wood stoves. They feed fuel automatically, use a fan to move combustion air and exhaust, and usually vent through a smaller, listed pipe that may run through a wall or up an existing chimney with a liner. The venting requirements come from the stove manufacturer, and they are strict about pipe type, length and termination.
Pellet stoves still need cleaning: ash collects in the burn pot, the heat exchanger and the vent pipe, and a partly blocked vent can push exhaust back into the room. Follow the manufacturer’s cleaning schedule, and have the vent checked as part of the yearly inspection. As with wood stoves, Acushnet and many other towns list pellet stoves among the installations that need a permit.
Signs to stop and call
- A roaring sound, very hot stovepipe or flames from the top of the chimney: get everyone out and call 911.
- Smoke coming into the room during normal operation.
- Black flakes or a tar smell much stronger than usual.
- A carbon monoxide alarm sounding: leave and call 911, then have the stove and flue checked.
Kindling, starters and first fires
The first fires of the season are a good time to warm the flue gently. Start with small, dry kindling and newspaper or commercial fire starters made for stoves, give the fire plenty of air, and build up over the first half hour. A cold flue drafts weakly at first; a small hot fire gets the draft established before larger loads go in. Watching how the stove behaves on those first fires, how fast it lights, whether any smoke escapes when the door opens, is a quick check that everything is working as it should.
Ashes and alarms
Put ashes in a metal container with a tight lid, kept outside and away from the house, decks and anything that burns; ashes can hold heat for days. And check smoke and carbon monoxide alarms before the season starts. Massachusetts requires CO alarms in homes with fossil-fuel-burning equipment, and wood stoves produce carbon monoxide too.
Sources we checked
- EPA Burn Wise: Best Wood-Burning Practices
- EPA Burn Wise: Choosing the Right Wood Stove
- NFPA 211: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances
- Town of Acushnet Building Department
- Mass.gov: Massachusetts law about carbon monoxide detectors
General information for homeowners from Chimney Champ’s New Bedford. It cannot stand in for an inspection of your own chimney, and questions about code are decided by your local building or fire official.