A gas insert is a sealed firebox that slides into the opening of an existing fireplace and vents through a new liner run up the old chimney. Done well, it turns a drafty, smoky hearth into a heater you start with a switch. Done badly, it can push exhaust back into the living room. The difference is almost all in the preparation: the state of the chimney before anything goes in, the way the liner is sized and sealed, and whether the gas line and permit are handled by the right people. This guide walks through the installation in the order it actually happens in a Kirkland house, then goes through what each part of a quote should cover.
Gas is already the norm in many Kirkland homes
In the Census Bureau's American Community Survey (2020–2024 sample), about 48.5 percent of Kirkland's occupied homes heat mainly with utility gas and 49.3 percent with electricity, while only about 75 households, roughly 0.2 percent, rely on wood as the main fuel. The survey does not count fireplaces, but those figures say a lot about how they are used here: mostly for ambiance and backup heat, in houses where a gas meter is often already on the wall.
That matters for an insert because the gas supply is usually the simplest part of the job. The harder parts are inside the chimney.
The installation, step by step
The order below is the one that avoids surprises. Skipping the first two steps is how inserts end up sitting in dirty, cracked flues.
| Step | Who handles it | Why it matters |
|---|---|---|
| Sweep and camera check of the existing flue | Chimney technician | Creosote and cracked tiles have to be dealt with before they are sealed out of sight |
| Measure the firebox and choose a model | Installer, with you | Width, depth and the height of the opening decide which inserts fit |
| Run the vent liner top to bottom | Chimney technician | Direct-vent units need sealed intake and exhaust through the full chimney |
| Extend the gas line and wire the blower | Licensed gas fitter and electrician | Gas piping and power are separate trades with their own rules |
| Permit inspection and first firing | City inspector, then installer | Confirms clearances, venting and gas connections before regular use |
Permits across the Northshore
Kirkland, Bothell and Kenmore all take permit applications through MyBuildingPermit.com, the regional portal that also handles inspection scheduling. Bothell handles residential mechanical replacements on its form 9, which has its own line for gas log inserts. Woodinville, outside that portal, asks for a permit whenever a furnace, heat pump, fireplace, stove or similar appliance is added, moved or swapped; its combined application lists both wood and gas fireplace inserts as fixtures.
An installer who offers to skip the permit is offering you a problem at resale. Woodinville says plainly that unpermitted work may have to be torn out.
Reading an installation quote
A complete quote separates the appliance from the work around it. Expect distinct lines for the insert and its trim kit, the liner and termination cap, any chimney cleaning or repair found during the pre-check, the gas line, electrical work, and the permit. If the liner is missing from a quote, ask why: a direct-vent insert cannot vent safely without one.
On our grid, a stainless liner runs from $1,900 to $5,900 depending on chimney height and configuration. The appliance itself varies too much by model and finish to price in an article. We begin with a $99 on-site inspection, plus tax, that is subtracted from the job once you approve our written quote, and after installation the insert is looked after on our gas fireplace service grid.
Frequently asked questions
Does a gas insert need its own liner?
Yes. A direct-vent insert draws combustion air in and pushes exhaust out through pipes that run the full height of the old chimney. The original flue is too large and too cold for the appliance to vent into on its own.
Is a permit required to install a gas insert in Woodinville?
Woodinville requires a permit to install, relocate or replace fireplaces and stoves, and its combined permit form lists gas fireplace inserts among the fixtures to declare. The city warns that unpermitted work may have to be removed and can draw fines.
Can I go back to burning wood after a gas insert is in?
Not in the same opening. The insert and its liner occupy the firebox and the flue. Going back to wood means removing both and having the chimney checked for a solid-fuel fire again.
What does yearly service on the insert run?
Our gas fireplace service is $189 to $479. The low end covers a routine cleaning and check; repairs involving parts sit higher.
Sources
- Census Reporter — ACS heating fuel — accessed September 29, 2026
- MyBuildingPermit.com — member jurisdictions — accessed September 29, 2026
- Bothell — Mechanical permit form 9 — accessed September 29, 2026
- City of Woodinville — Permitting FAQs — accessed September 29, 2026
- Woodinville — Combined permit form — accessed September 29, 2026
- City of Woodinville — Mechanical & Plumbing Permits — accessed September 29, 2026
Related services
