Locally-owned since 1977 • Licensed, bonded and insured in Washington (WA Contractor Reg. #HOMECCA785BD) • NATE-certified technicians • Carrier Factory Authorized Dealer
Furnace replacement in Issaquah, WA
When your furnace is failing, unsafe or simply too expensive to keep repairing, our Redmond branch will measure your Issaquah home and give you written replacement options with prices, incentives and financing. The estimate is free. Call (425) 645-0404 or send the form.
Issaquah has grown fast since the 1990s, so many homes still run the furnace they were built with. Units installed in the late 1990s and 2000s are now 15 to 25 years old, the range where replacement typically starts to make more sense than continued repairs.
What furnace replacement costs
Seattle-area figures from Angi, Seattle new furnace costs, updated July 2026. Not our prices; your written quote follows a visit.
| Item | Seattle-area estimate |
|---|---|
| Average installed furnace | About $4,683 |
| Common range | $2,762 to $6,683 |
| Natural gas furnace | $3,800 to $10,000 |
| Electric furnace | $2,000 to $7,000 |
| Labor share of the total | About 20 to 30 percent |
A replacement in a newer Issaquah home is often simpler than in an older one: if the existing furnace is already a high-efficiency model, the PVC venting and condensate drain are in place and can often be reused after inspection. Attic or crawlspace installations, duct repairs, or a move to a different location add cost.
Get a free estimateAn in-home visit and a written, upfront price before any work begins.
Three ways to replace a furnace in Issaquah
1. A new high-efficiency gas furnace. Straightforward for PSE gas homes. Two-stage or modulating models with variable-speed blowers are quieter and more even than the single-stage units common in older construction.
2. Dual fuel. A new furnace paired with a heat pump that heats in mild weather and cools in summer. It qualifies for the Energy Smart Eastside $1,000 rebate on qualifying brands (Energy Smart Eastside, heat pump incentives) and the PSE hybrid heat pump rebate of $1,500, plus up to $2,400 more for income-qualified households (PSE hybrid heat pump rebate).
3. All-electric heat pump. The furnace is removed and a ducted heat pump with electric backup takes over. Moderate-income households may qualify for the Energy Smart Eastside bonus of up to $5,000 on top of the $1,000 rebate, which requires a fully electric system with no furnace backup. Details on our Issaquah heat pump page.
Signs your furnace is due
- Age of 15 to 20 years or more, plus a major part failure such as the inducer, control board or heat exchanger.
- Repairs in each of the last two winters.
- Rising gas bills without a change in use.
- Rooms that no longer heat evenly, or a noisy blower.
- Rust, water damage or a cracked heat exchanger found at a tune-up.
If a carbon monoxide risk is found, we shut the furnace down and explain why. Otherwise, repair and replacement are priced side by side.
Features worth paying for
The biggest comfort difference between furnaces is not the brand but how they run:
- Burner staging: a two-stage or modulating burner spends most of the winter at low fire, so temperatures swing less and the furnace is quieter than a single-stage unit that is always at full blast.
- Variable-speed blower: moves air gently for longer, improves filtration, and makes adding a heat pump or AC later straightforward.
- AFUE rating: 95 to 97 percent models send very little heat up the vent, compared with 80 percent units.
- Communicating controls: some systems let the thermostat, furnace and heat pump coordinate staging for better efficiency.
We quote a good, better and best option when you want to compare, with the running cost difference explained, not just the price.
Plan the replacement before it fails
Replacing a furnace on a cold January night leaves little room to compare options or wait for incentives. If yours is past 15 years and a tune-up found wear, pricing a replacement ahead of time lets you choose the equipment, check Energy Smart Eastside and PSE eligibility, and schedule the install for a mild week. Energy Smart Eastside rebate codes are valid for up to 90 days (Energy Smart Eastside, heat pump incentives), so planning also keeps an incentive from lapsing. Financing options are included with your written estimate.
Cleaner air with the new furnace
The furnace cabinet and return plenum are open during a replacement, which makes this the easiest time to add a deeper media filter cabinet. A 4 or 5 inch pleated filter captures more fine dust and smoke than a thin filter, with less airflow restriction, and usually needs changing only once or twice a year. For households with allergies or during smoky summers, it is one of the most noticeable upgrades for the money.
Getting the size right
Many furnaces installed with new homes were sized with a generous margin, and later upgrades such as new windows or added insulation lower the load further. We run a room-by-room load calculation for the house as it is now. A correctly sized furnace runs longer, quieter cycles, heats more evenly and lasts longer than an oversized one, and it may allow a smaller, less expensive unit.
Ducts and airflow
Before installing, we measure static pressure and check the return. Undersized returns are a common reason newer furnaces run hot and loud. We also look for disconnected or crushed ducts in the attic or crawlspace, and seal leaky joints at the plenum. Duct work is priced as a separate line so you can decide what to include. In multi-level homes where one floor is always colder, this is also the moment to add a return, a zoning damper or a second thermostat, since the equipment and ducts are already open.
Venting, condensate and the water heater
High-efficiency furnaces vent through PVC and produce condensate that must drain reliably, with a pump where no drain is nearby. If an older gas water heater shared a metal flue with an 80 percent furnace, removing the furnace can leave that flue oversized for the water heater alone, so we check it and line it where needed. Outdoor PVC terminations are placed away from windows, doors and snow build-up.
Permit and install day
A furnace replacement in Issaquah generally needs a mechanical permit from the City of Issaquah Permit Center, and new wiring needs an L&I electrical permit (City of Issaquah, Do I Need a Permit?; City of Issaquah, electrical permits). We file them.
- Floors protected; gas and power shut off; old furnace removed and hauled away.
- New furnace set and connected to gas, venting, condensate, power and ducts.
- Gas pressure, temperature rise and combustion tested; carbon monoxide checked.
- Thermostat set up; filter and shutoffs shown; paperwork left with you.
Most furnace swaps take a day. Dual-fuel and heat pump conversions usually take two.
Warranty and Home Comfort Club
We support the manufacturer’s warranty on covered equipment parts, and we stand behind our furnace installations with a 1-year labor warranty from installation.
Join our Home Comfort Club, a monthly membership starting at $15 a month, and a new system we install gets extended labor coverage for as long as your membership stays active, up to 5 years from installation. Ask your technician or comfort advisor for the current plan details.
Issaquah furnace replacement FAQ
How much does a new furnace cost in Issaquah?
Seattle-area data puts the average installed furnace at about $4,683, with most jobs between $2,762 and $6,683 (Angi, July 2026). Your written quote follows a visit.
Can I get a rebate for replacing my furnace in Issaquah?
Rebates are mainly for heat pumps. Adding one to a new furnace (dual fuel) can qualify for Energy Smart Eastside and the PSE hybrid rebate; an all-electric heat pump may qualify for the Energy Smart Eastside bonus.
Should I replace my furnace with a heat pump?
If you want cooling too, or qualify for the Energy Smart Eastside bonus, often yes. Otherwise dual fuel or a new efficient furnace can be the better value. We price the options side by side.
Do I need a permit to replace a furnace in Issaquah?
Generally yes: a City of Issaquah mechanical permit, plus L&I for new wiring. We handle it.
How long does a furnace replacement take?
Usually one day; dual-fuel or heat pump conversions usually take two.
Is a two-stage furnace worth it?
For most homes, yes. It runs at low fire most of the winter, so it is quieter and keeps temperatures more even than a single-stage furnace.
Do you offer financing?
Yes. Financing options are included with your written estimate.
What warranty comes with your work?
We support the manufacturer’s warranty on covered equipment parts, and our labor warranty covers installations for 1 year from installation. Home Comfort Club members (monthly membership starting at $15 a month) with a new system installed by Home Comfort Alliance get extended labor coverage for as long as their membership stays active, up to 5 years from installation.
Why Choose Home Comfort Alliance in Issaquah?
Your Comfort is Our Promise
We promise...
Reliable heating, air conditioning, plumbing and electrical service, all from one trusted company.
To educate and guide you through your options so you’ll find the right solution at the right price.
Knowledgeable and respectful workers who ensure both your own comfort during the installation process, and lasting comfort from your home systems.
Outstanding service, communication, and follow-up, so your home is comfortable now and for years to come.
Get a furnace replacement estimate in Issaquah
A Redmond-based comfort advisor will measure your home and give you written options with incentives and financing.
Get an estimate
A Redmond-based comfort advisor will call you to set up your visit.