Heating, cooling and plumbing in Dunn Loring, from the Vienna town line to the Beltway.
Most Dunn Loring houses have Vienna mail, one corner drinks Town of Vienna water, and Fairfax County signs every permit. A gas furnace diagnostic is $99.
- Prices in writing, first
- Dedicated HVAC and plumbing teams
- Virginia license #2705192276
Get your price in writing
Mostly 1960s and 70s houses, with a newer pocket off Gallows Road.
Dunn Loring is nearly all houses: about nine in ten detached, the rest townhouses, and not one apartment building in the Census count. The decade a house went up tells us most of what we’ll find in it.
The Vienna-mail streets hold about three Dunn Loring homes in four, and nearly all of its 1960s houses. That one decade built about three homes in ten here, more than any other. A house that age usually has copper supply lines, cast iron drains, the original ductwork, and a gas furnace and gas water heater that went in venting up the same flue.
22027 is the newer end. Dunn Loring’s own ZIP covers only the east side, around Gallows Road and Sandburg Street, and its median owner home dates to 1991. About half its houses went up in the 1980s and 90s, right when polybutylene supply pipe was going into new construction. If you see gray plastic water lines stamped PB2110, that’s it.
Gas does most of the heating. About seven owner homes in ten burn natural gas and nearly one in four heats with electricity. A few dozen still run on oil; we don’t work on oil burners, but we’ll gladly price the switch to a gas furnace or a heat pump.
Gas furnaces, central air and pipes from two different eras.
Two dedicated teams, one for heating and cooling and one for plumbing, sent out from our Chantilly shop.
Heating
A no-heat call here is nearly always a gas furnace: an igniter, a flame sensor, a pressure switch, now and then a worn inducer motor. When a 1960s house finally gets a high-efficiency furnace, its exhaust moves to PVC through the wall, and the old flue the water heater still uses gets checked before anyone signs off.
Cooling
Central air sitting on a gas furnace is the usual setup, both sharing one blower. A house built in 1991 is on its second air conditioner at least, and sometimes the indoor coil and the copper line set never got changed with it, which is worth knowing before a refrigerant leak gets patched twice.
Plumbing
Copper and cast iron in the older houses, polybutylene in some of the 1980s and 90s ones, PEX wherever it’s been redone. Fairfax Water or Town of Vienna, it’s hard enough to leave sediment in a tank water heater, so a yearly flush earns its keep.
One price book, whatever the envelope says.
A 22027 house and a 22182 house pay the same, and so does one in Chantilly. You get the number in writing before any work starts.
- AC run capacitor replaced$240 to $370
- Refrigerant topped up$190 to $740
- Condensate drain cleared$175 to $420
- Repair diagnostic visit$99
- Drain cleaning, one fixture$200 to $800
- Main sewer line cleaning$550 to $1,650
- Leak detection$200 to $500
- Pressure reducing valve replacement$500 to $1,000
- Water heater, tank, installed$2,757 to $7,494
The figures come from the price book behind our plumbing page and our AC repair page. Replacing a gas water heater? The water heater estimator prices yours with the Fairfax County permit counted.
Ready to replace an old furnace or air conditioner? The HVAC estimator shows the installed range for a house your size before anybody visits.
Fairfax County signs every permit; the water comes from one of two places.
Your water
Most of Dunn Loring buys from Fairfax Water, and its 2026 report and service map put all of 22027, the 22182 streets and most of 22180 in the zone that typically gets Potomac water treated at the Washington Aqueduct’s Dalecarlia and McMillan plants. The exception is the southwest corner off Cottage Street, the streets named for colleges, which the Town of Vienna’s service map shows on Town water although they sit outside the town.
Reports: Fairfax Water (Washington Aqueduct water), 5.6 to 10.9 gpg; Town of Vienna (Fairfax Water and Washington Aqueduct water), 5 to 10 gpg.
Your permit office
Dunn Loring has no town government, and a Vienna address doesn’t put a house inside the Town of Vienna, so Fairfax County is the one office. It wants a permit every time a gas furnace or gas water heater is replaced, the same model in the same spot included, along with a chimney vent certification. Putting in a new heat pump or air conditioner counts as mechanical permit work too.
Permit pages: Fairfax County.
Your sewer line
Most houses here drain to Fairfax County sewer, where county code hands the owner the whole lateral, from the house to the main, including the part under the street. The Town’s sewer map takes in a couple hundred houses on the west side, Richelieu and Malraux Drives among them, and its service agreement does the same thing: the pipe from the main to the house is the owner’s.
Sources: Fairfax Water’s 2026 report and the Town of Vienna’s water and sewer maps and Fairfax County Code 65-6-5.
How Northern Virginia homeowners rate us.
5.0 stars across 884 Google reviews. Read them on our reviews page.
Voted a Nextdoor Neighborhood Faves winner two years running: 2026 in 30 Northern Virginia neighborhoods, 2025 in Emerald Chase (Herndon) and Hunters Run (Chantilly).
Listed in both the HVAC and Plumbing categories of Northern Virginia Magazine’s Best Home Experts directory, which is exactly how we’re built: a dedicated HVAC team and a dedicated plumbing team.
Our vans in Dunn Loring lately
In the last 30 days SwiftPro’s vans did heating and cooling repairs and heating and cooling maintenance in Dunn Loring, most recently on Tuesday, October 6.
Dunn Loring is 13 miles from SwiftPro’s Chantilly shop, and the van that comes to you is coming from the last job, not from the shop. SwiftPro charges no distance fees anywhere it serves.
More of our customers live around Dunn Loring than around our own shop in Chantilly.
I-66 up to Wolftrap Road, the Vienna town line over to the Beltway.
In 22027: Gallows Road past Fire Station 13, Sandburg Street, Arden Street, Harithy Drive and Journet Drive. With Vienna 22180 mail: Cottage Street and the college-named streets off it, Jackson Parkway, Stonewall Drive and Wedderburn Station Drive. With Vienna 22182 mail: Hollis Lane, Electric Avenue, Woodford Road, Notre Dame Drive and Westchester Drive. Next door:
Dunn Loring questions.
My address says Vienna. Is my house in Dunn Loring?
Quite possibly. In the 2020 Census about three Dunn Loring homes in four sat in Vienna ZIP areas, 22180 or 22182, and only the east end around Gallows Road uses 22027, which lies wholly inside Dunn Loring. Roughly, if your street is between the Vienna town line and the Beltway, from I-66 up to Wolftrap Road, you’re in Dunn Loring and in unincorporated Fairfax County, which is all a permit cares about.
Is my water from Fairfax Water or the Town of Vienna?
Fairfax Water, for most of Dunn Loring: every 22027 house, the 22182 streets and the bigger share of 22180. The Town of Vienna supplies the corner off Cottage Street with the college names, Carnegie, Bucknell, Wesleyan, Pepperdine and their neighbors, a few hundred houses in all. The name on your water bill settles it in five seconds.
How hard is Dunn Loring’s water?
It swings with the seasons. The Aqueduct water most of Dunn Loring gets measured 96 to 187 milligrams per liter in 2025, roughly 6 to 11 grains per gallon, at its softest in May and June and its hardest in December. Town of Vienna water runs 5 to 10 grains. Either one leaves scale in a tank water heater, which is why we put Dunn Loring tanks on a yearly flush.
My furnace and water heater share one flue. Does a new furnace change that?
Usually, yes. Close to half of Dunn Loring’s houses date from the 1960s and 70s, when a gas furnace and a gas water heater normally vented up one flue together. A high-efficiency furnace gets its own PVC vent, which leaves the water heater alone in a flue sized for two, and a lone water heater can draft badly in one that big. Fairfax County wants a chimney vent certification with the gas permit, so we look at the flue and price any liner or vent change up front, not halfway through the job.
What does an AC repair cost in Dunn Loring?
Same book as our other towns. Replacing a run capacitor is $240 to $370. Topping up refrigerant is $190 to $740. Clearing a clogged condensate drain is $175 to $420. On a 1990s system in 22027, we’ll also tell you honestly whether the coil and line set are worth another repair or whether you’re paying to keep a tired system going.
Vienna mail or 22027, give us a call.
Tell us your street and about when the house was built. We’ll tell you what’s typical for it, what it usually costs, and when we can be there.
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company serving Northern Virginia, including Dunn Loring, Vienna, Falls Church and McLean. SwiftPro holds Virginia contractor license #2705192276, is a Trane Comfort Specialist, Rheem Pro Partner and Mitsubishi Diamond Contractor, holds 5.0 stars across 884 Google reviews, was voted a Nextdoor Neighborhood Faves winner two years running, for 2026 in 30 Northern Virginia neighborhoods and for 2025 in Emerald Chase (Herndon) and Hunters Run (Chantilly), and is listed in both the HVAC and Plumbing categories of Northern Virginia Magazine’s Best Home Experts directory. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team. More at goswiftpro.com.
In Dunn Loring, SwiftPro repairs and replaces furnaces, heat pumps, air conditioners and ductless mini-splits, cleans air ducts and dryer vents, and handles plumbing from drains and leaks to water heaters and sewer lines, in 22027 and on the Vienna-mail streets alike.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr, Suite N, Chantilly, VA 20151, (703) 997-9757. Every town we serve is on the town-by-town guide.