Converting a Wood Fireplace to Gas in Seattle

Most wood fireplaces in Seattle are not a main heat source. Census data show only about 0.2 percent of Seattle homes heat mainly with wood, and about 61 percent use electricity. The fireplace is for evenings, and on many of the coldest, stillest evenings a burn ban rules it out. Converting it to gas means the fire is there when you want it, and the Puget Sound Clean Air Agency says natural gas and propane stoves and inserts are OK in both Stage 1 and Stage 2 bans.

There are two ways to do it. Gas logs set into the open firebox give the look of a fire for the least money. A sealed direct-vent gas insert costs more but heats the room. Either way the conversion starts with the chimney and the gas supply, because the old flue and the route for a gas line decide most of the price.

Signs you need this

• A wood fireplace that sits unused most of the winter
• Burn bans landing on the evenings you want a fire
• Smoke smell in the house after wood fires
• Gas already at the house for heat, water or cooking
• A chimney that needs work before it can burn wood again

How we do it

1. Inspect the fireplace and flueAt the free inspection we check the firebox, damper, flue and crown, and find where gas can come from.
2. Choose logs or an insertWe price gas logs and a sealed insert side by side, with what each needs from the chimney and the gas line.
3. Run gas and ventThe gas line is run to the fireplace with its own permit, and an insert gets a coaxial vent liner to the top of the chimney.
4. Install and lightLogs or insert are set, connected and lit. We check the flame, the venting and that the home has carbon monoxide alarms.

Gas logs or a gas insert?

Gas logs with a new gas line typically cost $1,500 to $4,500. They look good and add a little heat, but the damper stays clamped open, so the open fireplace still lets warm air out. A sealed gas insert with a vent liner typically costs $4,000 to $8,000 for a conversion. It closes off the fireplace opening and puts real heat into the room. Most people who want to sit by the fire in winter end up happier with the insert.

What if my house does not have gas?

About a third of Seattle homes heat with utility gas, compared with close to half in Bellevue, Kirkland and Edmonds. If there is no gas service at your street, or the utility cannot bring it to the house, propane is the alternative. PSCAA's burn ban guidance treats propane the same as natural gas. A propane conversion needs space for a tank and a line from it to the fireplace.

Does the chimney still matter after a conversion?

Yes. Gas logs vent up the existing flue, so it must be clear, sound and capped. An insert vents through its own liner inside the chimney, but the brick around it still has to be weather-tight, and a crumbling crown still leaks. Seattle's rule for unreinforced masonry chimneys, DR 5-2004, applies to chimney repairs, so if the stack needs work, we explain how that rule affects it and suggest confirming current requirements with SDCI.