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Furnace Installation

Furnace Installation in Seattle

Free Energy Consultations & Estimates for Seattle Homeowners

When your furnace needs replacing, the last thing you want is guesswork. Brennan Heating, Air Conditioning, Plumbing, and Electrical has been installing furnaces for homeowners throughout the Puget Sound region since 1987, and we’ve built our process around one goal: getting you the right system at the right price, with no surprises. Every installation starts with a free in-home energy consultation, so you’re never committing to equipment before you know exactly what your home needs.

As a Lennox dealer, we offer energy-efficient, dependable furnace products backed by our own workmanship guarantee. Our energy consultants work through every detail with you, from equipment selection to available rebates and financing options.

Ready to get started? Call us at (425) 610-9839 or schedule your free furnace installation estimate online. We’re available 24/7, including weekends.

Why Seattle Homeowners Trust Brennan Heating, Air Conditioning, Plumbing, and Electrical

Replacing a furnace is a significant investment, and who installs it matters as much as what gets installed. Our technicians are NATE-certified, the industry’s leading credential for HVAC professionals, and our firm holds EPA Certified Firm status. We’ve earned the Angie’s List Super Service Award for 13 consecutive years and carry an A+ rating as an Accredited Better Business Bureau member.

None of that happens without consistent communication and care on every job. Honesty, integrity, and service aren’t taglines for us; they’re the reason tens of thousands of Puget Sound region homeowners have trusted us with their homes. We also offer same-day service, weekend appointments, and a maintenance membership with priority scheduling for members who want ongoing peace of mind.

What to Expect from a Brennan Furnace Installation

Our process starts before a single tool comes out. One of our energy consultants visits your home, evaluates your heating needs, and walks you through your options, including equipment size, efficiency ratings, and budget. Proper load calculation helps confirm the furnace we recommend fits your home, not just your square footage on paper.

Once you’ve chosen your equipment, we handle the installation with care and full attention to local requirements. Furnace installations in the Seattle area typically require a mechanical permit, and our familiarity with King County and surrounding county requirements helps keep the project on track. A standard furnace replacement usually takes one to two days; installations involving ductwork modifications may take a bit longer. After the work is done, our technicians don’t disappear. We back every installation with our workmanship guarantee and remain available to help keep your equipment running well for years to come.

Financing & Rebates for Seattle Furnace Replacements

A high-efficiency furnace costs more upfront than a standard model, but the gap is often smaller than it looks once you factor in available incentives. We offer flexible financing through GreenSky on approved credit, so a short-term budget concern doesn’t push you toward a lower-efficiency system that may cost more to run over time. Plan details are available on our financing page or during your free estimate.

Our Comfort Advisors stay current on state, federal, manufacturer, and utility rebate programs so you don’t have to research them yourself. Puget Sound Energy, for example, offers rebates of up to $3,000 for qualifying furnace, heat pump, and water heater upgrades for eligible customers in its service territory. Rebate eligibility depends on the equipment you choose and your utility provider, and we can walk you through what applies to your situation.

Schedule Your Free Furnace Installation Estimate

There’s no obligation and no cost to find out what a new furnace installation in Seattle would look like for your home. Call Brennan Heating, Air Conditioning, Plumbing, and Electrical at (425) 610-9839 to schedule your free estimate or book online. We’re available 24/7, and every installation we complete is backed by our workmanship guarantee.

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    Highly Recommend
    “We had a duct & dryer vent cleaning done yesterday, and this company and its staff were phenomenal! The techs that came to our house were very kind & professional, with great information about the job they performed in preparation for an installati”
    - Rodney S.
    Thank you Josh & Brennan. Job well done!
    “Kudos to Josh, he was fantastic! Appt for yearly furnace maintenance check before it gets cold. Josh arrived on time and got right to work. He did a thorough check & found no problems.”
    - Ernest D.
    A Great Experience From Start to Finish
    “Rick Clements from Brennan made the process easy, straightforward, and clear. I had a lot of questions about which system to choose for my situation, and he helped guide me to the right one without trying to upsell. Definitely recommend.”
    - Jonathan L.
    Two thumbs up!
    “Bryan & Michael arrived early as I requested and worked hard to clean the furnace vents, returns, and ductwork, including the dryer vent. Our daughter had recently used Brennan & recommended the company. I am delighted with the results.”
    - Janie H.
    Thank you!
    “Very professional, friendly & communicated so well! They performed maintenance and cleaning on both our AC and Furnace. We love Brennan and are so glad we had them install our systems, 14+ years ago, and have kept them going strong for us!”
    - Linda K.
    Great Customer Service
    “The services provided by the Brennan staff were outstanding. Sergio & James were on time, completely explained the 5 W's before starting, they were efficient, cleaned up as they worked, explained how each part of the system functioned.”
    - Steve S.
    Brennan Was Our Savior!
    “Extremely fast service even after our major windstorm! Vincent arrived and verified our generator hookup was working properly and professionally explained our setup and how to properly cut over power to our generator while our power was out.”
    - Mike S.
    Two Thumbs Up!
    “Bryan and Michael arrived early as I requested and worked hard to clean the furnace vents, returns and ductwork including the dryer vent. Our daughter had recently used Brennan and recommended the company. I am very happy with the results. I felt the price”
    - Janie H.
    • Smarter, Safer, & More Efficient
      From high-efficiency HVAC installs to LED lighting upgrades and surge protection, we’re here to improve the way your home feels—and functions—year-round.
    • Award-Winning Care
      Multi-year Angie’s List Super Service Award winner with an A+ BBB rating, Brennan is Seattle’s trusted partner for top-tier heating, cooling, and electrical services.
    • Integrity Meets Innovation
      From certified energy consultants to licensed electricians, our team brings you forward-thinking solutions backed by time-tested values of honesty, reliability, and expert care.
    • Trusted Since 1987
      With decades of experience and thousands of satisfied customers, Brennan delivers worry-free heating, cooling, and electrical solutions with service you can count on.
    Your Comfort is Our Commitment

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    Proudly Serving Western Washington King County, Snohomish County, Pierce County, Kitsap County, Mason County

    From Seattle to the Sound—We’re in Your Neighborhood If you don’t see your community listed, contact us to see if we can still help!

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