How Much Does Furnace Replacement Cost in Seattle?
A gas furnace replacement in the Seattle area typically runs $4,000–$9,000 installed — equipment, labor, and permit — with about $5,500 as the common midpoint. Your exact number depends on the furnace size and efficiency you choose, the condition of your venting and ductwork, and city permit fees, which commonly add $150–$450.
Typical Seattle-area ranges
Gas furnace replacement
$4,000 – $9,000 typical ~$5,500
New high-efficiency furnace, installed — equipment, labor, permit
Seattle permit fees commonly add $150–$450. Complex jobs and premium equipment run higher.
Sources: Home Comfort Alliance Seattle furnace guide (2026) · HVAC Project Cost — Seattle, WA (2026)
These are typical Seattle-area market ranges compiled from published cost guides (Angi, HomeGuide, and Seattle-area 2025–2026 cost studies) — market context, not a quote from Glendale Heating & Air Conditioning. Your home's size, equipment, ductwork, electrical, and permits change the number. National figures are marked; Seattle-area labor typically runs above national averages.
When does replacing a furnace make more sense than repairing it?
The rule of thumb we give Seattle homeowners: if your furnace is past 12–15 years old and facing a major repair, replacement usually wins financially. A new high-efficiency unit cuts fuel use, restarts the warranty clock, and ends the repair-every-winter cycle.
If the system is younger and the fix is small, repair it. We put the repair-versus-replace math in writing on every visit so you can decide with real numbers — not pressure.
Why do Seattle furnace quotes vary so much?
Quotes differ in scope, not just price. One bid includes the permit, code-required venting, disposal of the old unit, and a workmanship guarantee; another leaves those out and adds them later as change orders.
Seattle-area labor also runs above national averages, and older local housing stock — 1920s brick, 1950s ramblers, split-levels with tight furnace closets — regularly adds venting, electrical, or sheet-metal work a national cost calculator can't see. Our in-house sheet metal shop fabricates transitions and plenums to fit your home instead of forcing a one-size-fits-all install.
What moves the price up or down?
Size and staging
A correctly sized furnace comes from a load calculation — an oversized unit short-cycles and an undersized one runs constantly. Two-stage and modulating furnaces cost more up front and run quieter and more evenly.
Efficiency (AFUE)
Higher-AFUE condensing furnaces cost more but burn less gas every month. They also need PVC venting and a condensate drain, which affects the install price.
Venting and code work
Washington code updates mean older venting often has to be corrected at replacement time. If a bid doesn't mention venting, ask why.
Permits
Seattle-area mechanical permits commonly add $150–$450. A quote without a permit line is a red flag, not a discount.
Ductwork condition
Leaky or undersized ducts can steal a chunk of the efficiency you're paying for. Sometimes a duct repair belongs in the project; sometimes it doesn't — we test rather than guess.
An honest quote includes
- Exact equipment brand and model numbers
- Labor, permit, and disposal of the old furnace
- Any code-required venting or electrical work, priced up front
- Warranty terms — equipment and workmanship — in writing
- One total, with what-happens-if-we-find-a-problem spelled out
Cost questions Seattle homeowners ask
How much does a new furnace cost installed in Seattle?
Typical Seattle-area gas furnace replacements run $4,000–$9,000 installed, with about $5,500 as a common midpoint. High-efficiency equipment, venting corrections, and complex installs push toward the top of the range; permits commonly add $150–$450.
How long does a furnace last in the Pacific Northwest?
Most gas furnaces last 15–20 years here, and regular maintenance is what gets you to the top of that range. Past 12–15 years, put major repair money toward replacement instead.
Should I replace my furnace with a heat pump instead?
In many Seattle homes, yes — Washington's mild winters are ideal heat-pump territory and utility rebates can take $1,500–$6,000 off qualifying conversions. We quote both options when it makes sense so you can compare real numbers.
Does Glendale charge for a furnace replacement estimate?
No — estimates on new system installations are free, and we also give free second opinions on replacement quotes from other companies. You get a written scope with one total before any work begins.
Ready for comfort you can count on?
Whether it's a furnace that quit on a cold morning or a whole new system, the Glendale team is ready. Honest pricing, expert work, and 87+ years behind every visit.
Hours & Emergency
- Mon–Sat: 8:00 AM – 7:00 PM
- Sun: Emergency On-Call Only
- Emergency line: (206) 243-7700