Looking for an HVAC company in Fairfax? The post-war ramblers and colonials around Old Town Fairfax and George Mason are some of Northern Virginia's most renovated housing, and their HVAC has to keep up. We've serviced Fairfax homes for decades, a straight run up Route 123 from Woodbridge.
Why us?
Serving Fairfax
The City of Fairfax and the neighborhoods around it, Mosby Woods, Fairfax Circle, Kings Park West, are largely 1950s-to-70s ramblers, split-levels, and colonials under a canopy of mature oaks. Most have been renovated at least once: finished basements, kitchen bump-outs, master additions. The HVAC problem is that the ductwork and equipment often never caught up with what the house became.
That's the pattern in most Fairfax calls we run: a system sized for the 1962 floor plan straining to condition 40% more finished space, ducts that were never extended properly into the addition, and an electric panel already full when the homeowner wants an EV charger. We fix the system as the house is now, real load calculations, duct corrections, ductless heads for the spaces central air can't honestly reach.
Leonard Splaine has been family-owned since 1956, as long as some of these neighborhoods have existed. We've never sold to private equity, a real person answers our office day or night, and one number covers cooling, heating, water heaters, electrical, and generators, with GMU-area landlords and long-time homeowners alike on our books.
Our Services
AC repair, heating, heat pumps, and ductless for Old Town, Mosby Woods, and the neighborhoods around GMU.
Fairfax's mature tree canopy is lovely and brutal on air conditioners: oak pollen mats the coils every spring and shade-side units corrode quietly. We run same-day AC repair through Old Town, Mosby Woods, and Fairfax Circle, fixing tired compressors, leak-prone original line sets, and airflow problems in much-renovated homes at a straight, flat-rate price.
Fairfax homes heat with everything: gas furnaces in the colonials, heat pumps in the renovations, and a surprising number of boilers and even oil systems in the older houses near Old Town. We repair all of them the same day, and we're one of the last companies in the region that still services oil heat, which matters on some of those 1950s streets.
The most common Fairfax install isn't like-for-like, it's finally sizing the system for the house as renovated. We run a real Manual J on the home you actually live in, additions and finished basement included, correct the duct runs that never got extended, and turn estimates around the same day, with financing available.
Fairfax's additions, sunrooms, converted garages, and GMU-area basement apartments are exactly what ductless mini-splits are for. As a Mitsubishi Diamond Contractor we install quiet single- and multi-zone systems that give those spaces their own heating and cooling without butchering the original ductwork.
Heat pumps are increasingly the replacement of choice in Fairfax, especially in renovations chasing efficiency. We repair every brand and install high-efficiency inverter systems, plus dual-fuel setups that keep a gas furnace as backup, a good match for the older, draftier housing stock around the city.
Under Fairfax's oaks, a spring tune-up is less optional than most places: pollen-matted coils are half the early-summer breakdowns we see here. We clean coils, check refrigerant and capacitors, clear condensate drains, and flag what's wearing out, with priority scheduling and waived diagnostics for maintenance plan members.
Brands
We repair every major brand and install new systems from the best of them. We're a Lennox Premier Dealer and a Mitsubishi Electric Diamond Contractor.
Current offers
Trust comes first, but fair deals don't hurt. Every offer below is available to every Fairfax customer, every day.
Special Offer
On a New Carrier System
0% APR with 60 equal monthly payments on qualifying new Carrier systems, financed through Wells Fargo and subject to credit approval. Sale period August 1 – November 20, 2026. Mention this offer when you book and we'll run the numbers on your replacement.
Expires: 11/20/2026
Special Offer
On a New Lennox System
Rebate up to $1,300, paid as a Lennox Prepaid Mastercard®, on a qualifying Lennox home comfort system, or combine a rebate up to $1,100 with 0% financing for 60 months. Buy July 6 – August 14, 2026; install by August 21. Qualifying system required; see us for details.
Expires: 08/14/2026
Special Offer
Plus 3% Off When You Pay by Cash or Check
Valid ID required. Applies to service visits. Cannot be combined with other discounts or offers. Ask about our 3% discount when paying by cash or check.
Expires: 12/31/2026
Why us
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Reviews
Real reviews from real Leonard Splaine jobs across Fairfax and Northern Virginia, from same-day AC repairs to full system installs. We've earned our 4.9-star average the slow way: answering the phone, showing up on time, and doing right by every home.
Lynn Gilbertson Google review Kyle provided emergency holiday weekend service when our a/c was completely out with 104F "feels like" temperatures. He quickly diagnosed and fixed our system, with solutions for avoiding similar problems in the future. We are grateful to Kyle and Leonard Splaine!
Katie Kada Facebook recommendation Couldn't have asked for better service! Leonard Splaine was timely, honest and did a wonderful job replacing our very outdated AC unit. We plan to use them again for any service or replacement in the future and we'll recommend them to our friends and family.
I will definitely use this company again! Our AC went out on one of the hottest days of the year. They answered and came to the rescue! Family owned and very kind. Technician was knowledgeable and quick.
Ankur Mundra Facebook recommendation I've used Leonard Splaine the last 5 years. They are professional, provide quality service, and answer my questions and concerns. Michael Ford came out this year to do my spring maintenance as well as eztrap installation and condenser coil cleaning. He did an excellent job.
Candace Bond Google review They were such gentlemen and seemed to be very knowledgeable and honest. They were also very patient and took the time to answer all of our questions. I would highly recommend these guys.
A/C stopped working on the hottest day of the year, so far. They came over the same day and had it up and running in no time. The price was reasonable and the tech was great.
Our Team
Every Fairfax visit is handled by real, named people who treat your home like their own. We're family-owned, 70 years in, and three generations of the same family crew. When you call Leonard Splaine, you reach these folks. Learn more about us.
Ted Leonard 3rd-Generation Owner 
Gary Leonard 2nd-Generation Owner 
Johnny Baker General Manager 
Erin Simmons Office Manager 
Brian Boyce Service Manager 
Brad Hoskins Field Supervisor 
Ira Sacknowitz Install Manager 
Ricky Seminario Comfort Advisor Where we work
Headquartered on Occoquan Road in Woodbridge, Fairfax is part of Fairfax County, and our techs cover the surrounding towns every day.
Don't see your town? If you're in Northern Virginia, call us. Odds are we've got a truck nearby.
Good questions
The things homeowners ask us most. Anything else, the phone's faster than the internet.
Both. We work Old Town Fairfax, Mosby Woods, Fairfax Circle, and Kings Park West weekly, and our service area covers the surrounding county neighborhoods too.
Very. It's the most common Fairfax problem we see: the addition got minimal ductwork off an already-maxed system. Depending on the space, the fix is duct corrections, a right-sized replacement, or a ductless head dedicated to the addition. We'll tell you which honestly.
In most cases, yes. We run a large fleet out of Woodbridge and hold room in the schedule for same-day repair calls across Northern Virginia. Call before noon and we can almost always be there the same day. Earlier in the day is better during peak season.
For residential HVAC, our diagnostic fee is $89. It covers a real diagnosis and a straight, written price before any work starts. Maintenance members have the diagnostic fee waived when they proceed with the repair. Ask us about the membership. Replacement estimates for HVAC systems, water heaters, electrical panels, and EV chargers are always free.
Yes. We work with multiple financing partners and pass along manufacturer promotions as they run, including 0% and low-monthly-payment options on new systems. Tell us your budget and we'll build options around it.
All of them. Our technicians repair every major brand of furnace, heat pump, AC, boiler, and water heater. For new installations we're a Lennox Premier Dealer and a Mitsubishi Diamond Contractor, including ductless mini-splits, and we also specialize in Carrier.
We do. We're one of the last companies in Northern Virginia that both services oil heating systems and delivers home heating oil and off-road diesel. If you have an oil furnace or boiler, you only need one phone number.
Yes. Alongside heating and cooling we install air filtration, whole-home humidifiers, UV purification, and air purifiers, a big help during Northern Virginia's pollen seasons and dry winters. Ask about it during any air conditioner or furnace visit, or book an air quality assessment on its own.
Yes, and it matters. Leonard Splaine has been owned and run by the same family for three generations, since 1956. We haven't been bought by private equity, and we're not going to be. When you call us, you're dealing with people whose name is on the trucks.
Same-day service across Northern Virginia. Talk to a real person, day or night.
