Open 24/7 for emergencies
The diagnostic visit is $99, and a run capacitor replaced is $240 to $370 from our published price book.
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AC and heat pump repair in the City of Fairfax and the county side, priced from a published book before any work starts.
5.0 stars across 1,132 reviews
One of our HVAC technicians beside an outdoor unit at a Northern Virginia home, the vans at the curb.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own HVAC installersA dedicated heating and cooling team, separate from our plumbers
Price in writing firstYou see every option priced before anything is ordered
What it costs
The same price book as our AC repair page. The diagnostic visit is $99, and the common parts ride on the truck, so most of these get fixed on the first visit.
Run capacitor replaced
$240 to $370
Contactor replaced
$290 to $425
Condensate drain cleared
$175 to $420
Refrigerant topped up
$190 to $740
Blower wheel pulled and cleaned
$300 to $440
Refrigerant leak found and repaired
$1,850 to $2,700
or $31/mo at 0% APR for 60 months
Repair diagnostic visit
$99
Monthly figures: 60mo @ 0% APR on each starting price, the whole price financed, on approved credit. Longer plans lower the payment and cost more in total. The lender sets the final terms. How financing works
Often same-day, and we will tell you honestly when we can get there.
With Comfort+ membership, $20 a month or $199 a year, the diagnostic visit is included, any service is 15% off, and the cooling and heating maintenance visits are part of the membership.
Recent work
What our technicians found and fixed on visits in Fairfax, from their notes on each job.
October 2026
An indoor coil freezing up on a system short of refrigerant, priced by the pound, with insulation on the suction line and a water safety switch recommended alongside it.
August 2026
Water in the auxiliary pan had tripped the overflow switch: an unglued PVC fitting on the condensate drain was leaking onto the furnace. Glued and tested, the system cooled again, and a weak capacitor and a loose exhaust joint were written up to replace.
July 2026
No cooling on the first floor: the outdoor fan ran, but the compressor wouldn’t start on a failed dual run capacitor. A new capacitor went in and the system cooled normally.
What’s different in Fairfax
In the City of Fairfax and Mantua, most houses heat with gas, so the cooling is a straight air conditioner outside and a furnace inside, and the two share one blower. When that blower wheel is caked in dust, both seasons suffer, and cleaning it is one of the cheaper fixes on the list.
Fair Lakes and Fair Oaks are younger, mostly 1990s, so most of those houses are on their second system by now. Kings Park West is among the most electric places with a Fairfax address, close to half its homeowners, which usually means heat pumps: outdoor units that work all year.
Repairs go ahead without paperwork. Replacing the system is permit work, and a Fairfax address can mean either office: the City of Fairfax inside the city line, Fairfax County everywhere else. The County also asks for an A2L certification with any new heat pump or air conditioner on the newer refrigerants.
Maintenance-plan AC visits are a bigger share of the work in Fairfax than in any of the other towns where we work most. That’s the visit where a weak capacitor or a matted outdoor coil gets caught in the spring, before a July afternoon finds it for you.
Neighborhood by neighborhood
Census figures for each place, and what that usually means for the air conditioning. Median year built and heat count owner-occupied homes only.
| Place | Median home built | Most homes are | Heated with | What the cooling usually is |
|---|---|---|---|---|
| Fair Oaks | 1995 | condo and apartment buildings, about 5 in 10 | gas, about 6 in 10 | Condo and apartment buildings: small splits and fan coils, roof or balcony condensers. |
| City of Fairfax | 1966 | single-family houses, about 5 in 10 | gas, about 7 in 10 | Older houses on their third or fourth system, usually a gas furnace with a separate AC. |
| Fairfax Station | 1982 | single-family houses, about 9 in 10 | gas, about 5 in 10 | 1980s and 90s houses, most on their second or third system. |
| Kings Park West | 1976 | single-family houses, about 7 in 10 | gas, about 5 in 10 | Older houses on their third or fourth system, usually a gas furnace with a separate AC. |
| Merrifield | 1990 | condo and apartment buildings, about 6 in 10 | gas, about 6 in 10 | Condo and apartment buildings: small splits and fan coils, roof or balcony condensers. |
| Fair Lakes | 1998 | townhouses, about 3 in 10 | gas, about 7 in 10 | 1980s and 90s houses, most on their second or third system. |
| Long Branch | 1968 | single-family houses, about 9 in 10 | gas, about 7 in 10 | Older houses on their third or fourth system, usually a gas furnace with a separate AC. |
| Mantua | 1968 | single-family houses, about 7 in 10 | gas, about 7 in 10 | Older houses on their third or fourth system, usually a gas furnace with a separate AC. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
Most of the Fairfax Station Census place, in the table, has Fairfax mail, so it counts here.
What you’d notice
Plenty of Fair Lakes and Fair Oaks houses got their second air conditioner in the 2000s. If the label says R-22, that refrigerant stopped being made in 2020, so a leak on that unit is the moment to price the repair and the replacement side by side.
Usually the outdoor unit has stopped running. A hum with no fan turning is almost always the run capacitor; silence while the thermostat calls is usually the contactor.
That’s an airflow problem far more often than a refrigerant problem: a clogged filter, a matted coil, or a blower wheel packed with dust.
Choosing who fixes it
Questions worth asking anybody who comes out, us included.
A Fairfax mailing address can be the City or the County. It doesn’t matter for a repair, but for a replacement it decides who inspects, and a contractor should know which before quoting.
A company that prints what a capacitor or a contactor costs has already told you the number. One that won’t say until the tech is in your driveway hasn’t.
A healthy system drops the air somewhere around 16 to 22 degrees across the indoor coil. Low refrigerant means a leak, and topping it up every summer is the expensive way to find that out.
Some repairs aren’t worth doing on a 20-year-old system. The good answer shows you the repair price and the replacement price side by side and lets you pick.
Two of our crew going over a work order before the day's calls.
From our Google reviews
5.0 stars across 1,132 reviews. Read them on our reviews page.
I would gladly recommend them to anyone in the greater Fairfax/Alexandria area without reservation.
Swiftpro came out the same day I called when my AC was out and had it fixed in less than an hour after arriving.
Aaron and Marshal did a great job. There were professional and respectful. Aaron had AC units more efficient and maintenance free.
Questions
No, a repair doesn’t. A new system does, and who issues it depends on the side of the city line: the City of Fairfax has its own permit office, and outside the line Fairfax County treats a heating or cooling replacement as mechanical permit work.
Usually not a failing AC. One system cools two floors, heat rises, and the top floor sits at the end of the longest duct runs. Balancing the dampers, zoning, or a ductless head upstairs fixes it; a bigger unit doesn’t.
Not necessarily. Heat pump air feels cooler than furnace air, and every so often the system runs a defrost cycle that blows cool for a few minutes. If it’s cool all the time, or the outdoor unit is buried in ice, that’s a call.
The diagnostic visit is $99. The common repairs: a run capacitor $240 to $370, a contactor $290 to $425, a condensate drain cleared $175 to $420, refrigerant topped up $190 to $740. A refrigerant leak repair runs $1,850 to $2,700.
Fix the cheap parts on almost anything. Think twice about a big repair on a system over 15 years old, and about any leak on an R-22 system. The HVAC estimator prices a new system in about a minute, so you can put the two numbers side by side.
Ready when you are
Call, or send the form at the top. The tech prices the repair from the book before starting, and if it’s the end of the road you’ll hear that first.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Fairfax and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,132 reviews on Google, Angi, Yelp, the BBB and Facebook. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
From SwiftPro Heating, Cooling & Plumbing in Chantilly. Housing figures are the Census Bureau’s American Community Survey, 2020 to 2024, for each place named; permit, water and sewer facts link to each office’s own page and were checked in September and October 2026.