AC repair in Fairfax.
AC and heat pump repair in the City of Fairfax and the county side, priced from a published book before any work starts.
- Prices in writing, first
- Common parts on the truck
- Dedicated HVAC team
Get your AC repair priced
Most Fairfax houses cool with an AC beside a gas furnace.
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 has the most electric heat of any place with a Fairfax address, which usually means heat pumps: outdoor units that work all year.
A repair needs no permit. A replacement does, 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.
What’s cooling the houses across Fairfax.
Census figures for the owner-occupied homes in each place, and what that usually means for the air conditioning.
| 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. |
| 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. |
| 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. |
Fairfax houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
The City of Fairfax
- Median home built1966 Census
- Built before 1980about 7 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes aresingle-family houses, about 5 in 10 Census
- Heated withgas, about 7 in 10 Census
- Rentedabout 3 in 10 Census
- Gas heat means a furnace inside and a separate air conditioner outside, sharing one blower, so a tired blower shows up in both seasons.
- Older houses often have returns too small for today’s systems, and a starved return is one of the ways an AC freezes up.
The Fairfax County side
- Built before 1980about 3 in 10 Census
- Built since 2000about 4 in 10 Census
- Most homes arecondo and apartment buildings, about 4 in 10 Census
- Heated withgas, about 6 in 10 Census
- Rentedabout 5 in 10 Census
- Condo cooling is often a small split or a fan coil, and the building may control the roof and the refrigerant lines.
What AC repair costs in Fairfax.
The same price book as our AC repair page. The diagnostic visit is about $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
- Repair diagnostic visitabout $99
Often same-day, and we will tell you honestly when we can get there.
On the Family Care Plan, repairs are 15 percent off, and the AC and heating inspections are part of the plan.
What a failing AC in Fairfax usually does.
The air coming out is warm
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.
It runs all day and never cools
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.
There’s water around the indoor unit
Shut it off and call. A blocked condensate drain is a cheap repair and an expensive ceiling.
How to pick the best AC repair company in Fairfax.
Questions worth asking anybody who comes out, us included.
Do they know which permit office you’re under?
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.
Do they publish prices?
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.
Do they measure before they sell refrigerant?
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.
Will they tell you when it’s the end of the road?
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.
What our customers say.
I would gladly recommend them to anyone in the greater Fairfax/Alexandria area without reservation.
Great experience with the SwiftPro cooling tech. After a previous AC repair visit, they recommended condenser coil cleaning for max efficiency. Same tech, same excellent experience. 100% recommend this independently owned shop.
SwiftPro was able to schedule a repair visit that same day when our a/c was blowing warm air. They sent out a qualified technician who communicated effectively and resolved our problem quickly. He also made a few recommendations to keep our unit in working order. Thanks Jaime for the great job!
5.0 stars across 884 Google reviews. Read them on our reviews page.
AC repair questions from Fairfax.
Do I need a permit to fix my AC in Fairfax?
Not for a repair. Replacing the system is permit work: Fairfax County lists it as mechanical permit work, and the City of Fairfax runs its own permit office inside the city line.
Why is my Fairfax house hotter upstairs than down?
Usually not a failing AC. One system is cooling two floors, heat rises, and the top floor sits at the end of the longest duct runs. A damper adjustment, a zoning change or a ductless head for the upstairs fixes it; a bigger unit doesn’t.
My Kings Park West heat pump blows cool air in winter. Is it broken?
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.
How much does AC repair cost in Fairfax?
The diagnostic visit is about $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.
Should I repair it or replace it?
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.
AC repair in the towns next door.
More from SwiftPro in Fairfax
Tell us what your AC is doing.
Call, or book online and pick a window. 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 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 884 Google reviews. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr, Suite N, Chantilly, VA 20151, (703) 997-9757. Book online, read our reviews, or see every town we serve.