Heating, cooling and plumbing in Oakton, sewer side and septic side.
Condos and townhouses by Route 123, big lots on septic toward Vale Road. What we find in Oakton homes, what it costs, and who signs off on the work.
- Prices in writing, first
- Dedicated HVAC and plumbing teams
- Virginia license #2705192276
Get your price in writing
Three kinds of house behind one Oakton address.
Oakton isn’t one kind of house, and which kind you live in decides most of what we find when we get there.
Along Chain Bridge Road and Blake Lane it’s condos, apartments and townhouses, most of them built since 1980 by the county’s own account. In the Oakton Census place close to two in three homes are townhouses or units in condo and small apartment buildings, and about four in ten owners heat with electricity, which here usually means a heat pump and an electric water heater.
North of Jermantown Road, Oakton Road and Waples Mill Road the lots get big, usually more than an acre a house, in the headwaters of Difficult Run. Fairfax County’s plan keeps public sewer out of that watershed, so plenty of those houses run on a septic tank and a drainfield instead of a county main.
In between are the older single-family streets the county names, like Grays Oakton between Blake Lane and Chain Bridge Road. About four in ten homes in the Oakton Census place went up before 1980, and a house that age usually has copper supply, cast iron drains, and a gas furnace and gas water heater sharing one flue.
Heat, cooling and plumbing from one shop.
A dedicated HVAC team and a dedicated plumbing team, out of our shop in Chantilly about eight miles west of Oakton.
Heating
Oakton is close to a coin toss: a little over half the owner homes burn gas in a furnace, and about four in ten run on electricity, usually through a heat pump. Our Oakton furnace repair page prices the common no-heat repairs on both kinds.
Cooling
In the electric half of Oakton the outdoor unit is the heat as well as the cooling, so it never gets a season off. Capacitors, contactors and condensate drains are priced on our Oakton AC repair page, and duct cleaning and dryer vent cleaning each have a page of their own.
Plumbing
Sewer or septic decides where a drain call ends: at the county main, or at a tank in your yard. More than a third of the homes in the Oakton Census place went up in the 1980s and 90s, inside the years grey polybutylene supply pipe was going in, so it pays to know what yours is.
One price book, on either side of Jermantown Road.
Our prices don’t change with the town or the size of the lot, and 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 visitabout $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
They come from the price book behind our plumbing page and our AC repair page. For a new water heater, the water heater estimator prices yours with the permit already counted.
Pricing a new furnace, heat pump or air conditioner? Start with the HVAC estimator, which gives the installed range for your house size before anybody visits.
Fairfax County signs off, and your lot picks the sewer.
Your water
The county’s own map puts Oakton inside Fairfax Water’s service area. Fairfax Water’s 2025 results ran from 3.0 to 10.8 grains per gallon by plant and month, which is moderately hard to hard.
Reports: Fairfax Water, 3 to 10.8 gpg.
Your permit office
Oakton is unincorporated, so there’s no town office in the middle: Fairfax County issues every permit. Swapping a gas furnace or a gas water heater takes one even like for like, along with a chimney vent certification.
Permit pages: Fairfax County.
Your sewer, or your septic
On county sewer you own the whole lateral, from the house out to the county main under the street. On septic, county code wants the tank pumped at least once every five years, and the Health Department sends plumbing inside the house to a plumber and the tank and field outside to a licensed septic contractor.
Sources: Fairfax County Code 65-6-5 and the county plan for Oakton’s Fox Lake sector and the Health Department’s septic page.
What our customers say.
They gave me a 4 hour window but were out at the property within the hour.
I reached out to them after 6 pm when our AC unit stopped cooling the house and they had someone out the next morning.
They managed to come the same day that I called about a leak which was helpful.
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.
All of 22124, sewer side and septic side.
On sewer: the condos, townhouses and older streets along Chain Bridge Road, Blake Lane and Hunter Mill Road. Often on septic: the big lots north of Jermantown Road, Oakton Road and Waples Mill Road, out to Vale Road and Fox Mill Road. Next door:
Oakton questions.
Does all of Oakton have public sewer?
No. Fairfax County’s plan leaves much of the land north of Jermantown Road, Oakton Road and Waples Mill Road outside its sewer service area to protect the Difficult Run headwaters, a policy the Board of Supervisors reaffirmed in 1989, so many big-lot houses there use septic. One pocket north of I-66 and west of Jermantown Road was brought into the sewer area after septic systems there failed.
Who issues building permits in Oakton?
Fairfax County. Oakton has no town government of its own, so a gas furnace or gas water heater replacement goes through the county, even when the new one matches the old, and comes with a chimney vent certification. SwiftPro’s water heater estimator counts the permit in every price.
How hard is Oakton’s water?
Oakton is inside Fairfax Water’s service area, and Fairfax Water measured 3.0 to 10.8 grains per gallon across its two plants in 2025, harder in the fall. That’s enough to leave sediment in a tank water heater every year, which is why SwiftPro suggests a yearly flush.
Does SwiftPro work on the big lots out toward Vale Road?
Yes, all of 22124, from the condos near I-66 to the houses on Vale Road and Fox Mill Road, with the same crews and the same price book. If the house is on septic, say so when you book, so the plumber knows where the drains end.
What does an AC repair cost in Oakton?
The same as anywhere SwiftPro works in Northern Virginia: a run capacitor is $240 to $370, a refrigerant top-up $190 to $740, and a blocked condensate drain cleared $175 to $420. About four in ten Oakton homeowners heat with electricity, and on a heat pump the same outdoor unit does the heating too, so a summer repair is worth doing properly.
Sewer side or septic side, call us.
Tell us your street and whether the house is on sewer or septic. We’ll say what’s typical for houses like yours, 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 Oakton, Vienna, Reston and Fairfax. 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 Oakton, 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, across 22124.
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.